CAN wiring

[20B]

I am about to wire up my SLM to my existing SDL and M800 setup. I will make a new CAN loom with resistors to replace the old direct connection of SDL to M800. Question is can I have a few 'spare' DTM connectors hanging off the CAN bus not connected to anything to use for future add ons so I dont have to hack up the CAN bus in the future ( MDD or Beacon ) or will it upset the link to other devices ?
Also can I have a Deltron CAN connector wired up in addition to the M800 CAN connector on the CAN network so I can mount it at a more easily accesable place and use both? Anyone else's ideas or setups would be helpful before I go crazy with the heatshrink

[IJ.]

No probs I do this with my CAN bus in the hope that one day I can add my TRANS controller into the loop

[20B]

After spending a little bit of time making up a nice loom and soldering resistors I plugged it all in and switched on the SDL, hey presto it automatically recognises the new SLM on the CAN comms screen and we are away ! Thanks motec for making another quality product that ' just works' first time.

[rdmahurin]

Just to clarify - if you connect a CAN device with a drop that is longer than 500mm, you need to add a 100 ohm terminating resistor?

I am curious as to why the resistor is 100 ohms, and not the standard 120 ohms listed in most publications.

How critical is the cable impedance and the number of twists? 120 ohm is the usual for J1939, but regular twisted 22 AWG and one twist per 50mm is listed in the manual (this number seems to vary widely with different wire manufacturers).

I ask because I may need to add CAN devices on the fly and adapt as I go (most likely at the circuit unfortunately).

[Holmz]

Just to clarify - if you connect a CAN device with a drop that is longer than 500mm, you need to add a 100 ohm terminating resistor?

You also need one with a loom shorter than 500mm... My 250-mm loom needed one... I used a 50-Ohm.

I am curious as to why the resistor is 100 ohms, and not the standard 120 ohms listed in most publications.

You actually need a couple of 100 ohm resistors so that is 50-Ohms by time you are done with 2.