I’m setting up an M1 system that hasn’t been used in over six years. It was in a house I previously owned, and I want to use it in a new house we are building.
When the M1 system was last used, it had three M1DBH data hubs on the RS485 bus. I remember one of them (the “last one in the chain”, I think) having the RJ45 terminating plug in the first unused RJ45 jack. Unfortunately, I can’t find the M1DBH that has the RJ45 terminating plug. How/where can I get a new terminating plug?
Assume two connected DBH’s, i.e., M1 RS485 bus -> DBH1 -> DBH2, and DBH1 only has three devices plugged in to it. Does the cable from DBH1 to DBH2 plug into DFH1’s jack #4 (first unused jack) or jack #9 (last jack)?
If you have only 3 devices connected to M1DBH#1 you will connect from J4 on M1DBH#1 to J1 on M1DBH#2 using a crossover cable — see the M1DBH Instructions for the pin out of the crossover cable. Connect your devices to M1DBH#2 and you can install a Jumper on the last “device” connected and not need the RJ45 with resistor built in. You will need to remember later if you install a new device to move the Jumper.