TSSI BD8 MANUAL BD8 BLOCK OCCUPANCY DETECTOR
BD8_REV_2.5 The Signaling Solution
The Signaling Solution, Inc. PO Box 25 West Terre Haute, IN 47885 Copyright 1996-2005 The Signaling Solution, Inc. All Rights Reserved TSSI BD8 MANUAL TABLE OF CONTENTS
1. 2. 3. 3.1 3.2 4. 4.1 4.2 4.3 4.4 5. 6. 6.1 6.2 6.3 INTRODUCTION ...........................................................................................................................................5 BD8 OPERATIONAL FEATURES...............................................................................................................6 PLANNING YOUR TRAIN DETECTION SYSTEM .................................................................................7 PROTOTYPICAL SIGNALING SYSTEMS............................................................................................7 SPECIAL MODEL RAILROAD APPLICATIONS ................................................................................9 CONVERTING TO COMMON RAIL WIRING.......................................................................................10 ELECTRICALLY INDEPENDENT CABS............................................................................................11 FINDING THE CAB COMMON OUTPUTS.........................................................................................11 INSTALLING THE LAYOUT COMMON WIRE ................................................................................12 CONNECTING NON-DETECTED BLOCKS .......................................................................................13 POWER ROUTING THROUGH SWITCHES ..........................................................................................14 INSTALLING YOUR BD8...........................................................................................................................17 PHYSICAL INSTALLATION OF THE BD8 BOARD .........................................................................20 SELECTING THE WIRE SIZES ............................................................................................................22 CONFIGURING YOUR BD8 DETECTOR ...........................................................................................24 NORMAL OPERATIONAL MODES.............................................................................................24 SELF TEST MODES ........................................................................................................................25 SOFTWARE VERSION NUMBER.................................................................................................26 6.3.1 6.3.2 6.3.3 6.4 6.5 6.6 6.7 6.8 7. CONNECTING TO THE TRACK BLOCKS.........................................................................................28 CONNECTING THE OUTPUTS ............................................................................................................29 STANDING TRAIN DETECTION .........................................................................................................32 TESTING YOUR BD8 DETECTOR INSTALLATION .......................................................................34 TROUBLE SHOOTING SUGGESTIONS..............................................................................................34 CUSTOMER SUPPORT ..............................................................................................................................38 TSSI BD8 MANUAL 7.1 7.2 TECHNICAL ASSISTANCE ...................................................................................................................38 LIMITED WARRANTY ..........................................................................................................................38 LIST OF FIGURES
FIGURE 3-1 TYPICAL ABS-APB BLOCK SIGNALS .............................................................................................8 FIGURE 3-2 TYPICAL CTC SIGNALS.....................................................................................................................8 FIGURE 3-3 HIDDEN JUNCTION DETECTION .....................................................................................................9 FIGURE 3-4 HIDDEN HOLDING OR STAGING YARD ......................................................................................10 FIGURE 4-1 TAP WIRE CONNECTED TO LAYOUT COMMON ........................................................................12 FIGURE 5-1 POWER ROUTING SWITCH SET FOR MAIN LINE........................................................................14 FIGURE 5-2 POWER ROUTING SWITCH SET FOR SIDING..............................................................................15 FIGURE 5-3 POWER ROUTING AND SEPARATE SIDING DETECTION.........................................................15 FIGURE 5-4 POWER RAIL ROUTING TO MAIN LINE .......................................................................................16 FIGURE 5-5 POWER RAIL ROUTINE TO SIDING...............................................................................................16 FIGURE 5-6 POWER ROUTING WITH STRAIGHT STOCK RAIL COMMON..................................................16 FIGURE 6-1 DC CONTROL WITH BD8 DETECTOR BOARD ............................................................................18 FIGURE 6-2 COMMAND CONTROL WITH BD8 DETECTOR BOARD.............................................................18 FIGURE 6-3 BD8 BOARD ASSEMBLY DIAGRAM..............................................................................................19 FIGURE 6-4 BD8 AND PANEL LAYOUT READY ...............................................................................................21 FIGURE 6-5 COMMAND CONTROL JUMPER POSITIONS................................................................................24 FIGURE 6-6 DC CONTROL, OCCUPIED-VACANT OUTPUT ............................................................................25 FIGURE 6-7 EAST-WEST REPORTING, SOUTH RAIL COMMON....................................................................25 FIGURE 6-8 EAST-WEST REPORTING, NORTH RAIL COMMON ...................................................................25 FIGURE 6-9 READING THE SOFTWARE VERSION NUMBER.........................................................................26 FIGURE 6-10 RAPID OUTPUT SEQUENCING .....................................................................................................27 FIGURE 6-11 SLOW SPEED OCCUPIED-VACANT SEQUENCING ..................................................................27 FIGURE 6-12 SLOW SPEED EAST-WEST SEQUENCING ..................................................................................28 FIGURE 6-13 DRIVING MULTIPLE LED'S FROM A SINGLE OUTPUT ...........................................................29 FIGURE 6-14 LED RESISTOR INSTALLATION METHOD.................................................................................31 FIGURE 6-15 CONNECTING INDUCTIVE LOADS .............................................................................................32 FIGURE 6-16 DC CONTROL WITH STANDING TRAIN DETECTION..............................................................33 FIGURE 6-17 ZERO OUTPUT THROTTLE MODIFICATION .............................................................................36 LIST OF TABLES
TABLE TABLE TABLE TABLE 6-1 6-2 6-3 6-4 RESISTANCE TABLE FOR WIRE .....................................................................................................22 COMMON RAIL AND OUTPUT CONNECTIONS...........................................................................23 GENERAL PURPOSE BD8 CONNECTIONS ....................................................................................23 RECORD OF SOFTWARE VERSION NUMBER..............................................................................26 3 TSSI BD8 MANUAL APPENDICES
APPENDIX I APPENDIX II TERMINOLOGY.................................................................................... 39 OPERATIONAL FEATURES..................................................................... 42 1) CURRENT SENSING............................................................................ 42 2) TYPES OF OUTPUT............................................................................. 42 OUTPUT CAPACITY................................................................... 42 OCCUPIED-VACANT DETECTION................................................. 43 DIRECTIONAL DETECTION........................................................... 43 LED ACTIVATION...................................................................... 44 LOGIC SIGNAL ACTIVATION........................................................ 44 RELAY ACTIVATION................................................................... 44 3) BUIL-IN SELF TEST............................................................................. 44 APPENDIX III OCCUPANCY DETECTION AND REPORTING.............................................. 45 1) OPTICALLY BASED SYSTEMS.............................................................. 45 2) MAGNETICALLY BASED SYSTEMS....................................................... 45 3) SWITCHED ELECTRICAL CONTACTS..................................................... 46 4) CURRENT DETETCION SYSTEMS......................................................... 46 RELAY CURRENT SENSING.......................................................... 46 TRANSISTOR CURRENT SENSING.................................................. 47 DIODE CURRENT SENSING........................................................... 47 ISOLATED CURRENT SENSING..................................................... 48 APPENDIX IV TRAIN CONTROL SYSTEMS....................................................................... 49 1) DC CONTROL SYSTEMS....................................................................... 49 TWO RAIL SWITCHED SYSTEMS.................................................... 50 COMMON RAIL SYSTEMS............................................................ 50 2) COMMAND CONTROL SYSTEMS..................................... ......................52 LIST OF FIGURES FIGURE 1 FIGURE 2 FIGURE 3 TWO-RAIL SWITCHED CAB CIRCUITS...................................................... 50 COMMON RAIL LAYOUT WIRING........................................................... 51 COMMAND CONTROL LAYOUT WIRING................................................... 52 LIST OF TABLES TABLE 1 TABLE 2 DIRECTION AND RAIL USAGE....................................................................41 OUTPUTS FOR DIRECTIONAL DETECTION MODE...........................................44 4 TSSI BD8 MANUAL 1. INTRODUCTION
The BD8 Block Occupancy Detector is the latest in train detection systems. It works with layouts using either Command Control or DC Control systems for operating trains. In addition, for DC Control systems, the BD8 can report block status in either "OCCUPIED-VACANT" form, or it can report in "VACANT-STANDING-EASTWEST" form. With the OCCUPIED-VACANT form of output, the BD8 is all you need for two color signaling. The VACANT-STANDING-EAST-WEST form of output is particularly helpful with hidden track. By having two LED's on your control panel, both will be on if the block is occupied and no cab is selected; when you select a cab, only one will turn on to indicate the direction the train will move. Best of all, because of the advanced techniques used, one BD8 board will provide train detection in 8 different blocks. And will do this for about the same cost as three or four normal block occupancy detector boards. A high level of electronic integration offers the BD8 complete with built-in test functions, power supply and PC board edge connector. We realize that most model railroaders have railroading as their hobby - not electronics. To give you access to the latest electronic technology, without getting you into the electronics field, your BD8 comes to you completely assembled and tested. You don't have to have any knowledge of electronics to use all of the board's features. Simply follow the detailed instructions in this manual to connect the board's 8 inputs to your blocks for train detection, and the 16 outputs to your signals or other output devices. Depending on how your layout is currently wired, it may involve no more than taping into 8 block common rail wires, and adding 2 wires per block to your signals! TSSI BD8 MANUAL 2. BD8 OPERATIONAL FEATURES
The BD8 Block Occupancy Detector is the latest state of the art device for sensing the presence of trains in sections of track, and providing control signals to activate signals or other devices on the layout. a. b. The capacity of each BD8 is to detect trains and control two color trackside signals for up to 8 separate blocks. Train detection is by current sensing. The BD8 will see the train no matter how long or short or how twisted the track is in the block. c. d. The BD8 works with your layout control system - either DC Cab control or Digital Command Control. Direct output of both OCCUPIED and VACANT status - you can operate two color signals with no additional hardware. e. BUILT-IN SELF-TEST provided to help with the installation and trouble shooting, and identify specific problems. f. There is a significant output capacity to operate both trackside signals and control panel indicators with no additional hardware. g. Output flexibility - you can operate LED's, incandescent bulbs or relays for direct control of signals and other special features or use the BD8 to provide logic signals to other circuitry or a computer interface if you wish. h. i. Modularity ­ You can add as many BD8 boards as you need for your layout. Each will handle 8 more blocks. Furnished assembled and tested. Just use the mounting hardware and card edge connector included with each unit, and follow the instructions, and you will have state of the art train detection and signaling system. j. Cost - there is NO other comparable train detection system with as low a cost per block as the BD8 - except our BD16 Block Occupancy Detector Board for 16 blocks! k. l. Power supply can be bought additionally from The Signaling Solution, Inc to suit your requirements. The printed manual can be ordered for $7.00. The online version of the manual can be downloaded for free from The Signaling Solution, Inc. website. Refer Appendix II for further details on the operational features. Some special features with respect to DCC also include the following: a. b. c. Our detection boards never need sensitivity adjustments. The boards are sensitive enough to detect a moistened finger placed on the track, but do not detect high humidity or require periodic sensitivity adjustments. Each detector element has a current rating of 3 amps (continuous duty), and will withstand brief overloads of up to 10 amps. Detects trains by monitoring current throughout a block. Trains are detected anywhere in the block, not just as they pass a photo-detector or magnetic detector. 6 TSSI BD8 MANUAL 3. PLANNING YOUR TRAIN DETECTION SYSTEM
Now is the time to plan your train detection system. You probably have a general idea of what you would like to accomplish. But, to help you clarify any issues that may be undefined, we would like to present some ideas that may be helpful. The prototype railroads have only one purpose for their signal system: to help trains stop safely before reaching another train, and obstruction, or other unsafe situation. Naturally, we may want to include signaling to add realism to our layout. But there are aspects about model railroads that have no prototypical equivalent. For example, how often does a prototypical train pull into a hidden staging yard, or under a hydrocal mountain? We will also give some suggestions about using train detection to help you operate your layout, especially those portions which are hidden from view. 3.1 PROTOTYPICAL SIGNALING SYSTEMS In the succeeding paragraphs, we have provided just enough information to help get you started. There are a number of books and magazine articles available that will help you expand your knowledge of the subject. And, if you are attempting to model a specific prototype in a specific era, the final guide will be the railroad's Employee Time Table and Rule Book. While the figures and signal arrangements may be considered "typical" or "AAR standard", each individual railroad is free to add to or even modify the AAR standards as it sees fit. The main focus of a prototype signaling system is to help the engineer stop his train safely. But they also want trains to be able to move as quickly as possible when they are not stopping. The key issue is stopping distance. There are three primary factors that determine stopping distance: the weight of the train, the speed of the train, and the slope of the track. Heavier trains take longer distances to stop, faster trains take longer to stop, and trains going down hill take longer to stop. Even if we are modeling a prototype signaling system, as modelers, our stopping distances are measured in inches no matter what our speed, and our available space is minuscule. So, we resort to selective compression. We will normally have our blocks as long as the typical train on our layout. Our passing tracks are usually the same length as well. Before the advent of Centralized Traffic Control (CTC) systems, railroads used Automatic Block Signaling (ABS) to signal for one direction of traffic, and Absolute-Permissive Block Signaling (APB) to signal for two directions of traffic. For both of these systems, the Timetable identified where and when meets and passes were to take place, and the rules of train superiority, by class and direction, told which crews to take the siding and which to use the main. Any exceptions to the timetable, such as temporary routings, extra trains, movements opposed to the normal traffic flow, were handled using written train orders. The train crews were responsible for setting the track switches as they came to sidings, and for leaving them in the normal position when leaving. With CTC installations, a remotely located dispatcher controls the switches and signals at passing tracks, but usually not at industrial spurs. The timetable is still used to provide the schedule for the trains. But meets and passes are controlled directly by the dispatcher; the rules of train superiority are suspended. 7 TSSI BD8 MANUAL One simple way to tell which type of signaling the prototype is using is to look at the signals at the entrance and exit of passing tracks. With ABS and APB systems, there are two signals, one facing each way, located near the switch points. These are called headblock signals. Trains on the frog side of the switch will stop before reaching the fouling point if the signal they see shows STOP. The signal they face as they approach from the point side indicates the condition of the main line block. The siding is normally not signaled. The signal seen when leaving the passing track area is an absolute signal. If it displays STOP, a train is not allowed to pass. You will normally find a telephone located near absolute signals so the crew can phone for instructions if they find an unexpected STOP aspect. A A Figure 3-1 Typical ABS-APB Block Signals With CTC installations, there are usually three signals protecting the end of a passing track. Since the timetable is no longer used to determine train superiority, the signals are used by the dispatcher to issue "orders" to the crews. The signal seen when approaching the points will show CLEAR to indicate a train routing on the main, will show APPROACH to indicate a routine on the siding, and STOP to indicate STOP. Some railroads will have a two head signal, with the upper head signaling use of the main, and the lower head signaling use of the siding. Thus, GREEN or RED routes a train onto the main; RED over GREEN or RED over YELLOW will route the train onto the siding. The yellow aspect indicates using approach speed into the siding. On the frog side, there will be one signal for both tracks. These are both absolute signals, and the dispatcher will set one of these signals to display either CLEAR or APPROACH to allow a train to depart. A A A A Figure 3-2 Typical CTC Signals It should be noted that, except at passing tracks and junctions, where the dispatcher issues "orders" by signal indication, the remaining signals are normal ABS-APB signals. And even the dispatcher controlled signals will have their aspects overridden by the ABS-APB detection circuits if trains are in the blocks ahead of the signals. 8 TSSI BD8 MANUAL With CTC, the track circuits that detect the trains will control the aspect display at trackside; but they will also indicate occupied blocks on the dispatcher's panel so he can see where trains are. And a special track circuit detects trains which are on dispatcher controlled switches and prevents him from throwing a switch beneath a train. This is indicated by the short detection blocks containing the switches in Figure 3-2. Usually, as soon as a train enters the switch itself, all three of the signals will automatically return to STOP. This automatically protects the rear of the train. Also, no matter what the type of signaling, the industrial tracks along the way are interlocked into the signal system. If the switch to a spur or the derail on the spur itself is not in their safe position, the signals protecting the entrances to the block will display STOP. Normally, this will be a permissive stop, allowing the crew to stop, and then proceed at restricted speed watching for a train or obstruction. 3.2 SPECIAL MODEL RAILROAD APPLICATIONS As modelers, we can include all of the signaling the prototype uses, especially along our visible track. But much of our track is hidden. It really doesn't make sense to install trackside signals in places where neither the operators nor spectators can see them. But it does make sense to provide train detection and display block occupancy to help us operate trains in our hidden track. There are two typical situations that we have on our layouts that would benefit from occupancy display. When installed as shown in the next several figures, train detection will allow you and your operators to function as smoothly over hidden track as you do with the visible track. N2 P2 N3 P3 S1 P1 N1 Figure 3-3 Hidden Junction Detection In this figure, the three blocks labeled N1, N2 and N3 are "normal" length blocks, probably about a trains' length. The blocks P1, P2 and P3 are "positioning" blocks. Each is about the length of an engine, and they are located so that they protect the fouling points of the switch. And block S1 is the switch itself, from ahead of the points to a little beyond the fouling points on the frog side. Each of these blocks has an occupancy detector connected, which controls a single "occupied" LED on a panel, which is visible to everyone operating trains in the junction area. The display panel would probably depict the track in the area in schematic form. In normal operation, an engineer might be told to "hold at the junction." He would move his train toward the junction, watching the display panel to see where his train was. As soon as the positioning block shows occupied, he stops his train. If the switch block shows occupied, he has run through the positioning block and is fouling the switch. He simply backs up until the switch shows vacant and the positioning block still shows occupied. 9 TSSI BD8 MANUAL The next situation that we modelers have that the prototype doesn't have is a hidden holding yard. Its arrangement of detection blocks, the display of occupancy on a panel, and the method of operation are very similar.
P5 P6 N5 P8 S2 P7 N4 N3 N2 P4 P3 P2 S1 P1 N1 Figure 3-4 Hidden Holding or Staging Yard Again, the blocks labeled "N" are normal blocks, those labeled "P" are positioning blocks, and the switch blocks are labeled "S." Also, the block arrangements shown in these two figures are detection blocks. The power routing blocks, if you are using DC control, will include the consecutive "P" and "N" blocks. 4. CONVERTING TO COMMON RAIL WIRING
If your layout is already wired for common rail power distribution, your installation will be somewhat easier. But, even so, there may be some minor alterations in wiring, primarily involving power routing through switches under some conditions. Begin by selecting your common rail. If your layout has already been wired using the common rail system, this step is done. All you need to do is remember which rail you picked! The common rail can be either the north rail or the south rail, it really doesn't matter. Incidentally, just for clarity, this manual is written assuming that your layout is an East-West railroad. If you think of your railroad as a North-South railroad, we suggest that you temporarily think of it as East-West. This will make it easier to read the manual. Otherwise, this manual would be almost twice as big. Every paragraph would have to appear twice - once written with "East-West", and once with "North-South." How do you know which is the north or south rail? It's very simple, really. Look at any section of track on your layout where a west-bound train moves from right to left. The south rail is the rail closest to you; the north rail is the other rail. If your layout is an oval of some kind, Linn Westcott suggested many years ago that you envision a north pole in the center of the oval. The rail closest to the center would then be the north rail. If he had lived in the southern hemisphere, his suggestion may have been different, but it doesn't matter. First, without common rail wiring, your layout wiring diagram probably look something like Figure 1 Two Rail Switched Cab Circuits. As you can see, each of the two cab outputs is routed through a cab select switch to the two rails of each block. There is no single wire shared by all of the cabs - each is totally independent. Not shown are wires, or switch points, used for routing power. Perhaps you have some additional toggle switches used to connect reverse loops or crossings. There are several steps to go through in making the conversion. We recommend that you make the conversion in simple, easy to correct steps. Doing all of the rewiring and then testing to see if it all works is very macho - but 10 TSSI BD8 MANUAL not very bright! Based on our experience with the conversion process, we are going to recommend a step-by-step approach which will minimize your aspirin consumption. 4.1 ELECTRICALLY INDEPENDENT CABS Cab independence, of course, is essential to common rail. This lets us connect any one output terminal of each together without causing any problems. The most obvious indication that the cabs are electrically independent is simple to see. Any two cabs that have separate power cords are electrically independent. If you have any of the dual throttle cabs on the market, you will have to do some experimentation to see if they are electrically independent. First, with the unit unplugged from the wall and the throttle outputs disconnected from the layout, use an ohmmeter to check for continuity between the two throttles. Measure from each output of one throttle to each output of the other, and reverse to ohmmeter leads as well to make sure that there are no internal diodes connected. In all of these resistance checks, look for infinite resistance or an open circuit indication. Any low resistance under 10 K ohms is a pretty good indication that the throttles are not independent. Then, plug the power supply into the wall outlet, leaving it disconnected from the layout, and set the output voltage of each throttle to 3 volts. With your voltmeter on the 10-volt DC or higher scale, measure the voltage between each output of one throttle and each output of the other. This will give a total of four voltage readings. In each case, you will read 0 volts if the throttles are independent; if they are not, you will measure +6 volts for one measurement, and -6 for another. If the two throttles in a dual power pack are not internally isolated, you can use only one of them in your new wiring. Then, reconnect only one of the throttles if they are not independent, or both if they are independent. 4.2 FINDING THE CAB COMMON OUTPUTS Once you have selected the common rail, identify which output of each cab is connected to the common rail through your cab select switches. Turn off all of the cabs for this next step. Pick any conveniently located block, remove any engines and cars from the block, and attach one of your ohmmeter leads to its common rail. Then, one at a time, select each cab and with the cab select switch for the block and touch your other ohmmeter lead to the outputs of the cab. One of the outputs will show a very low resistance, probably less than an ohm. The other output will show a much higher resistance. Confirm the reading by reversing the ohmmeter leads. In each case, the cab output currently connected to your common rail through the cab select switches will show a very low resistance. Mark the common rail output on each cab. Do this for all of your cabs: main line, yard or other local service cabs. When this is done, let's do a sanity check. Make a quick and dirty temporary connection between all of the cab common rail outputs that you just identified. Then, operate a train over the layout, using each cab and taking each route, siding or spur. Everything should still work just as it always did. 11 TSSI BD8 MANUAL If something isn't working that used to work, take the time now to identify the problem. There're only two things that could be wrong at this point. Either cabs that you thought were isolated really aren't, or the cab output you identified as being the common rail output was incorrect. Before proceeding, correct the problem. 4.3 INSTALLING THE LAYOUT COMMON WIRE Next, we will install the layout common wire. Review Section 6.2 to choose the correct wire size to use. If in doubt, use the next larger size. Use stranded wire, as it's much easier to pull around joists, risers and L-girders. And it will probably be easier to install multiple runs of smaller gauge wire than one run of very heavy wire. For example, use four runs of 10-gauge wire rather than one run of 4-gauge wire. Both approaches give the same effective resistance, but 10-gauge wire is probably as heavy as you would want to work with. Of course, use copper wire, not aluminum. You will have to solder connections to the layout common, and copper is much easier to work with. Then, run the layout common wire around your entire layout, bringing it near to all of the cabs, and close to all of the locations you have selected for BD8 installations. When the layout common is installed, make your permanent connections between the cab common outputs and the layout common. Wherever you need to connect a tap wire to the layout common wire, carefully skin about one inch of the insulation off each of the common wires and strip a couple of inches of insulation off the end of the tap wire. Then take the stripped end of the tap wire and wrap a tight turn around each run of the layout common. Solder each of these turns to the layout common using rosin core solder. This is shown in Figure 4-1 Tap Wire Connected to Layout Common. Solder tap wire to each wire in the layout common group - 4 places in this example Tap wire connects to BD8 layout common pins, cab common output, or non-detected block common rails Layout common shown run with four parallel wires Figure 4-1 Tap Wire Connected to Layout Common You may need a 100 watt or more iron or soldering gun to heat up 10 gauge wire enough to get a good connection. It's better to use a higher wattage, and complete the connection quickly, than to use a low wattage iron 12 TSSI BD8 MANUAL and take all day to heat the wires. This won't work well, and you'll probably have melted insulation all around the connections. Be sure that you physically secure the bare wires so they can't move and possibly contact other circuits. Wrapping the connections with electrical tape may also be a good idea. This will save you trouble in the future. Again, do a sanity check by running your layout to see that everything still works. At this point, the only problems were probably caused by the physical disturbance that came from running the layout common wires. Since you really haven't changed your existing wiring, it should be easy to locate and fix the problems. Make sure everything is working before you continue.
4.4 CONNECTING NON-DETECTED BLOCKS You will probably have blocks or other sections of track that are not going to be connected to your BD8 boards. This will normally be yard tracks and probably industrial sidings. At this time, you will connect the common rails of these areas of track to the layout common wire. For your non-detected blocks, we recommend that you make sure that each such block or section of track has gaps in the common rail to separate it from any adjacent detected blocks. Connect these sections of track to the layout common one at a time, and then test what you did. This way, you can keep any problems from growing to unmanageable proportions. Also, by doing a little at a time, you can keep your layout operational while you make this conversion. Select a non-detected block to reconnect. After the common rail has been separated by gaps from other blocks, disconnect all of your original feed wires from your cab select switches to the common rail. We suggest you cut these wires so that at least a few inches remain connected to the rail and accessible. If you make a mistake and cut the wrong wire, you can splice the ends back together. If not, you can use the wire still attached to the rail to make the connection to the layout common wire. At this point, the common rail for the block should be completely isolated electrically. Verify this by connecting a cab to the block, and all adjacent blocks, using the proper cab select switches. Set the cab output for a few volts, and measure the voltage in the block from its common rail to its power rail. Check throughout the block, including any switches or crossings. The only right answer is 0 volts. This shows that the common rail has been isolated. If you get a non-zero voltage reading, it means that there is still an original wire connecting the common rail back through the cab select switches to layout common. Or, you may not have put in all the gaps needed to isolate the rail. It's time to conduct a search and destroy mission to eliminate all of the old connections to the cab select switch, or to cut all necessary gaps. You may still have some wires attached to the common rail. These will be wires that pick up the stock rails electrically and route them to switch machine contacts for powering the frogs. Leave these wires in place. When the common rail has been isolated from all of the original feed wires, connect it to the layout common. Attach a tap wire as described in the prior section, and connect the other end of the tap wire to the common rail 13 TSSI BD8 MANUAL using the ends of the original feed wires you left attached to the common rail. If the block is particularly long, you may want to use several tap wires from the layout common.
Note: At this time, the cab select switch is only feeding the power rail; the common rail is now being fed by the layout common wire. Finally, finish work on the block by conducting another sanity check. Run an engine in, around and through the block using each of the cabs, checking each of the routes. Fix any problems. If the engine does not run everywhere in the block, this will probably be due to missing a connection between a tap wire and one or more of the common rail wires. Or, you may have attached a tap wire to a power rail feed. This would result in a short circuit in the block, and the engine won't run anywhere as long as the cab select switch is set for the block. Repeat this process for each non-detected block, checking as you go. While you are doing this, you are only taking one block out of service at a time, and only long enough complete its conversion. You don't have to cancel any of your operating sessions! When you have finished all such blocks, go on to the section below, Power Routing Through Switches. 5. POWER ROUTING THROUGH SWITCHES
Train detection may also have an effect on your power routing through switches. Figure 5-1 shows a normal power routing switch aligned for the main line. As you can see, both siding rails are electrically connected to the power rail "P", and any train on the siding will see no voltage and will therefore be stopped. An electrical contact is shown which operates along with the points to route power to the frog. Figure 5-1 Power Routing Switch Set For Main Line Figure 5-2 shows the same switch aligned for the siding. Now, a train on the siding sees both power and common rails and can move, while a train on the main sees two common rails and cannot move. As long as we don't want to detect a train on the siding while the switch is set for the main, everything is just fine. But, if we want to have a separate block on the siding, with a separate detector, the standard power routing won't work. 14 TSSI BD8 MANUAL Figure 5-2 Power Routing Switch Set For Siding Figure 5-3 shows the same track with separate train detection on the siding using detector C2, while detector C1 is looking at the main line. You can see that we need a gap in the siding common rail near the fouling point of the switch to separate the siding's common rail from the main line block. Here is where things get interesting. The common rail for the siding is always connected to layout common through the C2 block detector, and its power rail is simply a continuous stock rail through the switch. And, even with the switch set for the main, a train on the siding will run! Figure 5-3 Power Routing and Separate Siding Detection To solve this problem, we need to have an extra electrical contact that operates along with the switch to route the power rail through the switch. This means two single pole, double throw (SPDT) contacts are needed for a power routing switch with separate detection on the frog side. One contact routes power to the frog, the second routes the power rail from the point side to one of the power rails on the frog side. This is shown below in Figure 54. Both of these contacts move along with the points. Everything in the figure is shown with the switch aligned for the main. Note: Both siding rails are gapped near the switch's fouling point, and the main line block's power rail
is also gapped at the fouling point. With the switch as shown, the lower contact is connecting the main block power rail to the frog (F). The upper contact is connecting the main block power rail to the part of the main block beyond the frog (rail PM). The power rail on the siding block (PS) is not connected to anything (nc), and a train on the siding will be stopped, but
could still be detectable by C2 if there was a source of current to detect. We'll show you how to do that in a just a bit. 15 TSSI BD8 MANUAL Figure 5-4 Power Rail Routing to Main Line In Figure 5-5, the same switch is aligned for the siding. Note that the contacts move with the points, and the frog (F) is now connected to the C1 rail. The siding power rail (PS) is connected to the power rail for the main (P), and the main line power rail (PM) beyond the switch is not connected (nc). A train will now run on the siding, but remain stopped on the main. Figure 5-5 Power Rail Routine to Siding Just for completeness, we'll show the same switch wired with the straight stock rail as the power rail, and the curved stock rail as the common rail. In Figure 5-6, the common rails are connected to two separate detectors (C1 and C2). We assume that "P" is being fed by a cab select switch, and is routed by the upper contact to the power rail (PM) in the main line block beyond the switch. Figure 5-6 Power Routing With Straight Stock Rail Common The power routing we have shown above is something that you will have to add to any of your switches that will have separate detection on the frog side with power being routed through the switch. One at a time, make the modifications to each of your switches that will operate this way. Again, after each is modified with the extra
16 TSSI BD8 MANUAL electrical contact, do a sanity check and run a train through all related routes. Make sure it runs when it should run, and stops when it should stop. If something doesn't work right, fix it. You have probably not wired one of the contacts properly, or have not cut the necessary gaps. 6. INSTALLING YOUR BD8
You have probably heard the adage "Prior Planning Prevents Poor Performance," and model railroading is no exception. Before doing anything on your layout, we recommend you plan your complete signaling installation, even if you have only purchased some of the detectors and signals you will eventually need. 1. First, make a drawing of your layout showing all of the tracks: main line, sidings, spurs, hidden, visible, built, or planned but not yet built. 2. Then, identify each separate detection block and give it a number from 0 to 7. If your layout needs more than one BD8, assign a letter to each BD8 (BD8-A for the first, BD8-B for the second, and so on), and label the blocks with the BD8 letter and block number. For example, if you have two BD8s, the first will have blocks labeled A0 through A7, and the second will have blocks labeled B0 through B7. Assign the labels any way you want. The purpose is simply to know how and where to connect the wires. This drawing will be the master signaling system drawing for your layout. 3. Before continuing here, if your layout is not already wired for common rail power distribution, follow the instructions in Section 4, CONVERTING TO COMMON RAIL WIRING. The steps have been planned out so that you can continue to operate your layout even if the conversion takes weeks or even months. There is no need to shut down your layout completely while installing signaling. 4. The next step is to connect your BD8 boards to your layout. There are two types of connections to make.
· The first group of connections will merge the BD8 into your common rail circuit so that the BD8 can detect your trains. When you have finished connecting your BD8 into the common rail feeds to your detected blocks, your wiring will look something like if you are using DC control. It will look like if you are using command control. The steps in the remainder of this section will help you to complete the installation. · The second group of wires will connect your BD8 to your signals, display LED's or any other logic circuitry you may have. Since the connections to LED's, logic and relays are all slightly different, separate paragraphs below will describe the differences. These connections are not shown in the two figures below. 17 TSSI BD8 MANUAL
BLOCK 1 CAB SELECTOR BLOCK 2 CAB SELECTOR BLOCK 3 CAB SELECTOR
TO OTHER CAB SELECTOR SWITCHES C A B 1 C A B 2 C A B 3 C A B 4 C A B 5 NORTH RAIL CONTROL BLOCK 1 CONTROL BLOCK 2 CONTROL BLOCK 3 NORTH RAIL SELECTOR DECKS DETECTION BLOCK 0 DETECTION BLOCK 1 SOUTH RAIL BLOCK 0 BLOCK 1 OTHER 6 BLOCK DETECTORS UP TO 6 MORE BLOCKS TO OTHER BD8 BOARDS BD8 OCCUPANCY DETECTOR BOARD
COMMON (4 PINS) LAYOUT COMMON CONNECTION NOTE: Detection blocks (SOUTH rail) and control blocks (NORTH rail) can be different. Detection outputs from BD8 are not shown in this figure. Figure 6-1 DC Control with BD8 Detector Board
TO OTHER BOOSTERS C A B 1 C A B 2 C A B 3 C A B 4 C A B 5 C O N T R O L S T A T I O N N B O O S T E R BLOCK 0 S BD4 OCCUPANCY DETECTOR BOARD
COMMON (4 PINS) TO OTHER TRACK POWER FEEDS NORTH RAIL SOUTH RAIL BLOCK 1
OTHER 6 BLOCK DETECTORS UP TO 6 MORE BLOCKS TO OTHER BD8 BOARDS ON SAME POWER STATION BOOSTER COMMON CONNECTION NOTE: Gaps are only used to isolate frogs, or to separate boosters. For DCC, do not make ANY connections between the outputs of separate boosters. For other forms of command control, see your system manual for instructions. Cab connections to control station depend on the specific command control system used. Figure 6-2 Command Control with BD8 Detector Board 18 TSSI BD8 MANUAL 5. Connect only one end of one wire at a time. Just repeat that one simple step for each connection to be made and you can't lose. Figure 6-3 BD8 Board Assembly Diagram below shows how your BD8 and related items will look when ready for installation. For your reference, the major items are identified individually. Figure 6-3 BD8 Board Assembly Diagram The items shown are:
Item 1: BD8 Printed Circuit board, with top view shown. Item 2: Mode plug with positions for four mode jumpers (none shown). Item 3: Card edge connector; your BD8 plugs into this connector. Item 4: Contact 1 of the 36 contact fingers on the card edge connector. Contact 1 is labeled on the connector itself, and corresponds to the top left contact on the PC board. Contact A is immediately below contact 1. The top row of contacts are numbered from 1 to 18; the bottom row is lettered A-V. Letters "G", "I", "O", and "Q" are not used.
Item 5: Pan Head #4-40 stainless steel machine screw (2 places) used to fasten the card edge connector to the right angle mounting brackets.
Item 6: Flat #4 stainless steel washers (4 places) used to protect surfaces from the screws and lock washers. 19 TSSI BD8 MANUAL Item 7: Internal tooth #4 lock washer (2 places) used to secure the mounting screws and brackets. Item 8: Stainless steel #4-40 hex nut (2 places). Item 9: Round head #4 wood screw (2 places) used to attach mounting brackets to the mounting panel. Item 10: Right angle mounting bracket (2 places). Item 11: The surface mounted voltage regulators. Item 12: The LED blinks when the on-board power supply is functioning properly. 6.1 PHYSICAL INSTALLATION OF THE BD8 BOARD Figure 6-4 BD8 and Panel Layout Ready below shows the BD8 mounted to a flat wood panel ready for installation on your layout. 1. A piece of 1 x 6 six to eight inches long, or a similar size piece of plywood, is just fine. You will also need diagonal cutters, needle nose pliers, screw drivers and soldering iron with a maximum of 25 watt rating. 2. Then attach the panel in an easily accessible location on a table leg or from the bottom of an L-girder. You will find it much easier to prepare the panel as shown at your workbench. Doing this under your layout will
probably be more difficult. Remember that you will be running wires from the board to the blocks and your signals or control panels. 3. Plan how the wires will be routed from the board and to the layout.
Suggestion: Use cable clamps to keep the various cables from placing any strain on the card edge connector pins and out of the way. 4. Use a strain relief to protect the contacts on the card edge connector.
Suggestion: For the larger gauge wires to your tracks and layout common, we suggest you use a Cinch Barrier Block part number 9-140. The current Digikey catalog (1-800-344-4539) lists this with their part number CBB109ND. For the smaller gauge wires to your signals, a simple cable clamp will do. A nylon cable clamp from the Richco line (also available from Digikey) will do. They come in several diameters, so pick the right size for the wire bundle going to the signals. You want the clamp to hold the wires securely and keep them from putting strain on the connector pins. Incidentally, the screw barrier strip is a good idea for troubleshooting. It makes is easy for you to disconnect blocks, or to swap BD8 detectors to aid in fault isolation. The small cost for such strips is well worth it. 5. If the distance from the BD8 and the blocks is particularly short, and your engines are equipped with low current can motors, you can probably run your common rail feed wires using 22 gauge wire. If you use stranded wire and a tight cable clamp to keep the wires from pulling on the connector contacts, you could connect directly to the card edge connector. See Section 6.2 for more detail on selecting wire sizes. Since the wires to your signals will probably be 22 gauge or finer, a simple cable clamp will be adequate. Stranded wire will be easier to work with. You may want to consider using four-conductor modular phone cord. It's available almost everywhere, and at a very low price. The four wires in the bundle are color-coded and, while fairly fine, they are easy to work with. 20 TSSI BD8 MANUAL Figure 6-4 BD8 and Panel Layout Ready The major items in Figure 6-4 are as follows:
Item 1: Screw barrier strip with 9 positions. Item 2: Common rail wires for blocks 0-3 from contacts 1-4. Item 3: Common rail wires for blocks 4-7 from contacts A-D. Item 4: Layout common. Connect to at least 2 of the four contacts 5, 6, E or F. Item 5: 16 occupied and vacant wires to signals on contr