Home Forums General Discussion Technical Questions TAC50-04 CAN Issue

I have a 32-bit TAC50-04 giving me Local CAN issues. It is reporting Drive Comm Loss and a 1508 Brake failed to echo over CAN fault. Changed the Brake board still the same issue. Measured voltage on LCH & LCL and it was good. Is the resistance also supposed to be 60 ohms for the Local CAN or is it different? Have double checked all the wiring and connections. There is no battery, this is not a Synergy. What else communicates over Local CAN beside the Brake, Drive & CPUA? Would you try the CPUA next to replace? Appreciate any help. Thanks

I think the Local channel is 50 ohms, not sure though. First make sure all your suppressors are in place on all your contactors and fans. Then I’d probably try the 2407MC card, or SCRB for a DC drive.

Hey don’t mean take the thread off on a tangent but I’m trying to get my hands on a IMS laptop any help?

Call TKE. They will sell you one for the job

Secure all your can connections. Check your grounds. 60 ohms is correct . Should have around 2.5vdc on lcl hcl to ground. Replace cpua if all else fails

you actually are supposed to have 45 Ohms on the local channel. Channel 1 is local, 2 and 3 are hw and car that should have 60 Ohms. Configuration matters too, not just the resistance (i.e. under 30' = no termination, star patterns etc) 2.5vdc is correct on your channels.

This looks like a while ago but if still not solved try/look for a couple of different things. The brake system, believe it or not is pretty susceptible to noise and will cause a 1508 fault. A lot of times, because of the voltage required for the coils most folks don't run them separate from all the other runs to the machine. A comm loss on the drive is pretty common depending on if you have a 10K drive, DSD, or an Accord.


I would start with 2407MC for sure, but you may check the jumper config on the CPUA as well. If you have 60 ohms on the CPUA comm channel (local channel) then they are probably in the wrong config.

Still having LCH/LCL Issues with this car. Just replaced CPUA with brand new board and have swapped out brake board. Local CAN is reading about 45 ohms. Would the drive board possibly be causing this even though the Brake Board is also reporting Comm loss? Thought for sure it was CPUA. Is the LCH/LCL voltage supposed to be about 2.5/2.4 VDC like the other CAN channels? Any chance the IOC can cause this? Jumpers all check good on IOC and CPUA.

Also car will run for 10 - 20 minutes before faulting out with CAN CH 1 faults. Faults are 701, 1507, 1508 & 1515.

Appreciate any insight on this. Customer is getting upset.

The 2407MC could absolutely be causing your problem. The voltage levels are the same as for channel 2 & 3. Also make sure all your contactors have suppressors across their coils. And they are good.

Its an Accord Drive so it is a MCINV5ST board. So it is possible that board is bad. Will also check all the suppressors.

Any chance your losing your watchdog on the cpua?

Still having Local CAN issue with this car. Thought I found an issue with the Brake Contactor, but fixed it and still Local CAN is throwing Brake Faults and Drive Faults. Have replaced the CPUA, IOC, Brake Board, Drive Board (Accord Drive) and still keeps happening. Found Brake wires run in with High Voltage for Motor and moved them still getting Local CAN faults. Suppressor is on MC1.

Any other suggestions or ideas? I have never run into a Local CAN fault this difficult.

With all the boards replaced, it sounds like electrical noise.

Just to clarify the coil suppressors that TKE uses has a resistor in series with heat shrink tubing around it. The purpose being, if the suppressor (capacitor) shorts then no other associated circuitry/ boards are damaged. If the suppressor failed then the voltage drop across the resistor creates enough heat that the soldered joint connecting it melts, which you would not be able to see since it is inside heat shrink tube. Checking suppressors, for me, means pulling on them to see if they separate inside heat shrink tube.

Also its worth noting that another source of noise, is a bad incoming voltage suppressor assembly. This is the black box attached to the incoming 3 phase. There are some of these early on that internal components would break loose from controller contactor vibrations. You check them by unattaching the black box and shaking it. If it rattles, replace it.

Also if this is Synergy Product, I think the UCA board is on CAN channel 1

I've had this elevator sitting on INSP for a couple of days and it has thrown no LOCAL CAN faults (or any faults at all) the entire time. It only appears to throw the LOCAL CAN faults when it is running. Would that indicate more of a brake/motor noise issue or does that not mean anything?

You mentioned the suppressor on MC1 but BK1, EBRK1, MCP, the fan relay and possibly the fans themselves have suppressors too. The motor cable and the brake coil cable should have their shields grounded on both ends.
Probably time to put a scope on the CAN channel.

Thanks, Indirtwetrust. When you say scope the CAN Channel, what will I be looking for? I've never put a scope on a CAN Channel, only know to look for the 2.5VDC on the high & low side and the CAN resistance. There are also no suppressors on the BK1, EBRK or MCP. Only the Fan & MC1.

It’s probably a plug in module on those small contactors. If one is open or missing it could be your problem. When I say scope the CAN channel I mean to look at the waveform with an oscilloscope. Compare it to the channels that aren’t getting faults and see what happens when contactors pick & drop, brake picks & drops. Does it clean up when one board is disconnected, etc. You could also run a logfile to look at next time is shuts down and see what’s immediately preceding the fault.

There was a bulletin about adding suppressors when you had Car Light and Fan Shutdown relay, CLFS. They would be located behind main swing panel , on horizontal terminal strip ( of you have tall cabinet)

If this is the issue you should be able to inject high the I/O for CLFS ,or the I/O that controls controller fans- FAN. Not sure if you have IMS available.

Knowing that it only happens when running further confirms noise. Maybe just start replacing suppressors anyway, pn# 9804420. I pretty sure CLFS feature doesn't activate when on inspection.

Did this get resolved?

Had the same issue. Replace the cpua and power supply.