Multiple Unit (MU) FAQ
The LCRC100 Locomotive Controller has an advanced feature that sets it apart from all other live steam locomotive controllers on the market, Automatic Multiple Unit (Commonly referred to as “MU”) operation. Given the advanced nature of this system, we wanted to have this FAQ available to explain some things and answer some common questions we get about it. If you have questions that are not answered here, you can always reach out to us via our contact page.
How hard is it to install MU in my locomotive? - Not hard at all! once you have the LCRC100 system installed, it’s simply a matter of soldering the MU wires to the supplied GX12 connector and inserting the pins into the supplied plug. You will also need to mount the GX12 connectors to the ends of your locomotive. We supply an easy to read wiring diagram for all of this to make it easy.
Can I MU with any other locomotive? - You can MU with any other locomotive equipped with the LCRC100 locomotive controller, however it will not MU with other brands of locomotive controller.
Why a wired MU connector and not wireless? - That’s a good (and common) question! There are 2 main reasons… One is that the wired connection is a more reliable way to connect your consist together. The second reason is related to the first and that is “wireless signal clutter”. When you have many wireless connections in the same area on the same frequency, interference can result and interference causes data packets to be lost between the locomotives in the consist and the consist and the handset. Even digital radios (which we use between the handsets and the locomotives) are susceptible to being “stepped on” by many or more powerful transmitters. At a meet with many locomotives in operation, there could be 30 or more radios using the same frequency bands (and that also includes things like Wifi transmitters) which could cause poor operation. With that in mind, we opted to go with a wired connection, just like the real railroads!
Do all locomotives need to be facing the same direction? - Nope! When connected in MU, all locomotives will automatically orient themselves in the system to operate in the same direction. There is nothing you need to do to change engine direction.
Do all the locomotives in the consist need to have the same motor control? - Nope! You can MU and manufacturer with any motor control with any voltage and any wheel size and gear ratio together so long as they’re equipped with the LCRC100.
Do you need to adjust trim (such as in an RC car) to get the locomotives to run at the same speed? - Nope! Automatic MU operation automatically adjusts all the locomotive outputs in the consist to speed match each other. There’s nothing to adjust, nothing to fiddle around with, nothing to try and get right. Just couple, connect and run!
So, how do they know how fast they’re going? - When you setup the LCRC100 initially, you will “train” your locomotive on its abilities. This only needs to be done once and takes about 20 minutes. You will need to have your menu setting for gear ratio and wheel diameter set, and the speed sensor connected. The process then involves lifting the locomotive off its wheels (use of blocks is recommended), and enabling "Speed Mapping" for the forward and then reverse direction to be mapped. Your locomotive will run through it’s speed range which teaches the controller the specifics of your loco. After that, you’re good to go! (More instructions and a video tutorial will be released soon)
What if a loco in the consist can’t go as fast as the others? - The MU system matches speed across the entire consist for minimum and maximum speeds, which means the whole consist will only go as fast as the slowest unit can go, and will only start the consist moving at the fastest minimum speed. For instance, if you connect 2 locomotives that can go 10mph, the speed limit will be 10 mph. If you then connect a loco that can only go 6 mph, now the whole consist will be limited to 6 mph. If that locomotive does 12 mph in the forward direction, but only 6 mph in the reverse direction, the consist will do 10 mph in the forward direction, and 6 mph in the reverse direction. Minimum speed is taken into account to address differences in motor controller "dead band". When a locomotive is disconnected, the consist is renegotiated and the speed limits will be set to the minimum and maximum speeds of the locomotives remaining in the consist, or return to the normal state of the individual locomotive if no consist is present. All those changes are made automatically!
How does MU effect the sounds of my locomotive? - When in MU mode, all locomotives in the consist will have their prime mover sounds continue to operate as normal, with the prime movers synchronized to that of the master locomotive (the one with it's handset turned on). Horn and bell sounds will only come from locomotives at either end of the consist. The default will start with the handset connected locomotive, and can then be selected from the handset for which end of the consist you desire to act as the “front”. The volume up-down feature will control the sound volume of all locomotives in the consist.
Is there a way to see how much power is left in the batteries in the consist? - Yes! On the handset is the consist display screen and that screen will tell you direction and power status of the engines in the consist.
Will the MU system work with gas hydraulic locomotives? - We will soon release a version of the LCRC100 for gas powered locomotives like Titan Trains and RailSystems engines. It will have capacity for MU operations with electric powered equipment. We expect that to arrive next year, but do not yet have a firm date on that.
Can you use MU to operate DPU (Distributed Power Units) or rear end “Helper” units? - Currently no, however Integral Circuits will be looking into producing a Wireless Bridge that could be used for that.