Three RJ12 Throttle Jacks: The front panel of the UP5 has 2 RJ12 6 pin connections for any Digitrax LocoNet throttle (DT400, DT300, DT200, DT100, UT, BT2, etc.). Another throttle jack is located on the side of the UP5. This side throttle jack is very useful for connecting a local DS54 or other device that is a “dead end” on LocoNet. Note: The RJ12s in the front and side of the UP5 should only be used as throttle jacks and should not be used as LocoNet connections where the device you are connecting is daisy chained to another device beyond itself. 2 LocoNet Jacks are provided on the back of the UP5.
TRACK STATUS Indicator: The TRACK STATUS indicator is a bi-color LED that reports the power state for a local track section connected to the UP5 for monitoring. This LED will not be lit if the UP5 is not hooked up to a local track section to provide power. The RJ12 sockets provide throttle power when you hook up the UP5 to a local powered track section.
Mounting Holes: The Universal Panel has 4 corner mounting holes for #6 screw clearance. The panel is normally flush mounted in the fascia of the layout or module, and the network wiring is accessed and hidden behind the fascia.
Two RJ12 LocoNet Jacks: The rear of the UP5 has two RJ12 6 pin LocoNet jacks that are "daisy-chained" pin-for-pin. These are typically used with the LocoNet jumper plug coming from the previous Universal Panel in on one side, and continuing out on the other side with a jumper cable to the next Universal Panel in the network. You can use these two jacks in any convenient order for connection to other devices. You can use "splitters" to provide more connections if needed just be sure that they are 6 pin to 6 pin.
2-Local Track Power Terminals: There are two #6-32 right angle screw terminals provided at the rear of the UP5. Connect these to each rail of a convenient track section using 22 to 28AWG wire. These terminals can be hooked up either way to the rails. The TRACK STATUS led on the panel front will be lit when the local track has power. This allows individual UP5s to diagnose whether individual power boosters or "districts" are shorted. Note that the TRACK STATUS circuit and the throttles draw their power from this input, and the RJ12 jacks need this connection to provide extra operating power to throttles connected to them. Normally this Local track input should be wired to the track so that the unit can pick up track power.
2mm DC Power Jack: A 2mm DC power jack on the side of the UP5 allows you to provide additional power to run throttles when the local track section is not powered up. This is especially important when you are using throttles that do not require batteries. This jack also lets your UP5 act as a "battery saver" module by powering throttles that need batteries from LocoNet rather than from their internal batteries. You can power up to 9 additional UPs and/or URs from a single +12V to +15V DC supply. Digitrax PS14 is available from your Digitrax dealer or you may choose to use a power supply from Radio Shack, DigiKey, Mouser or other supplier. When one or more of these jacks are powered they will "keep alive" LocoNet even when the command station is off and all throttles plugged in will run off LocoNet Power and will conserve battery power.
Wiring Your Layout with LocoNet
There are no real restrictions on LocoNet wiring with respect to wire pairs. Most Digitrax customers choose to use 6 wire Telco type flat ribbon cables because they are cost effective, simple to wire and give superior network performance. We engineered LocoNet to use 6 wires because of several advantages outlined below. LocoNet can actually run on just 2 or 3 wires.
LocoNet can support a total cable length of up to 1,200 feet. No two devices should be connected by more than 600 feet of cable. This allows for the network to be split & branched in a free form style with no stringent connection rules for network transmission. You can "tree" or branch out network stubs wherever it is convenient for the layout and debugging or servicing. The single network termination needed is provided by the Command Station. We do not recommend looping the network back on itself.
You can purchase ready made 6 pin male RJ12 to RJ12 jumper cables of various lengths from many sources. Be sure to use 6 conductor and not 4 conductor plugs and wires. Alternately, you can crimp your own jumper cables. LocoNet cables should be wired pin 1 to pin 1. When you hold the plug with the tab up and look into the end of the connector, you will see, from left to right, white-black-red-green-yellow-blue wires. This arrangement is called a “reversing” cable in the telecom industry. The UP5 is "reversing" in that all pin 1s of the RJ12 jacks connect to one another.
1) In a 6 wire flat configuration, as crimped onto a RJ12 6 pin style plug, the left 3 wires are effectively a "mirror" image of the right 3 wires. This allows you to "daisy-chain" outlets without worrying about whether the cables are "reversing" or "non-reversing."
2) There are 2 ground and 2 LocoNet data connections, so the effective "loop resistance" is lower due to paralleled wires. This makes it possible to run LocoNet over greater distances than other command control systems.
3) If a ground or signal connection is broken or intermittent the network can still maintain a reliable connection. These types of faults are the greatest nightmare to locate and fix!
4) The two outside wires, typically Blue and White in a 6 conductor Telco ribbon, actually carry opposite phase copies of the master system rail packets, this is called RAIL SYNC. Because these are broadcast differentially in a single cable, we can accurately and reliably tap a remote Track booster anywhere along a LocoNet cable run. We can do this many thousands of feet from the Master Packet generator (Command station) with very good signal fidelity, even in the presence of a lot of noise and interference! Also, this signal is capable of supporting a number of low current draw modules that can tap on anywhere in the network.
5) The balanced nature of the cable and the way the signal currents propagate in this "RF Quad" configuration allow the lowest possible RFI radiation outwards, and EMC susceptibility or inward interference pickup. This is a good thing. This is part of the reason Digitrax's LocoNet handily passed the FCC Class B radiation Certification requirements.
6) The LocoNet philosophy and architecture were carefully crafted to allow "free-form" wiring with no termination or "linear-bus" restrictions. You can "star", "tee" into, branch or expand the network any way that is convenient for you. If you do choose to "loop" the wiring back on itself (like a snake biting its tail) be sure that the outside 2 Railsync wires have a matched polarity! The center 4 pins of the RJ12 can be plugged in either orientation.
These are the reasons we would recommend the loop around the layout be a 6 conductor ribbon type wire. The wire guage in the range of 22AWG to 28AWG is OK. Telco uses typically 26AWG. If you don't mind the extra work, you could use round 3 pair cables. It is best to stay with a fixed color to pin number in the jacks throughout the layout to prevent later problems debugging!
We find it best to break up this "backbone" wiring into sections. Each section will be a run of cable connected by male-male 6 conductor cords with RJ12 plugs on each end. This allows the network to be quickly disconnected and isolated for fault-finding or expansion. The Digitrax Universal Panels (UP1, UP2, UP3 & UP5) are connection panels that are very convenient for quick layout hook up. They come in a variety of configurations to suit the needs of most layouts. You just plug in your cables and you are ready to play. Obviously it is cheaper to use 6 conductor dual wall plates and wire them in parallel around the layout. This will take you a little more time but will save money. The main down-side to this is that if any of the cables are disturbed or yanked on, it is very time-consuming to try to repair a "birds nest" of small wires under the layout! The choice is up to the you!
Your LocoNet wiring scheme is very flexible and easy to wire. It was designed to be "plug & play" because we know you would rather spend your time running your trains instead of troubleshooting the wiring. The primary concern really boils down to having a physically secure and maintainable wiring strategy and discipline. The "glow" of low price wire and fixtures quickly fades, as you become the poor individual who has to trouble-shoot a maze of "spaghetti" that was disturbed by someone who tripped over "some wires" under the layout!!