Need help with Elk M1XSP->RCS TR40 Thermostat Communication

[autophil]

I'm unable to get a RCS TR40 to communicate with the M1XSP. The M1XSP is bus enrolled and has been supporting a M1DBH without problems. M1XSP jumpers and switches are set in accordance with Elk's Installation Manual for the TR40 (i.e. Baud=000, Mode=1001;JP3=1,JP2=0;JP1=0;Address=1000). I've checked (and rechecked) the M1XSP->TR40 wiring for terminations and continuity. The TR40 powers up and the WDU communicates with the TR40 controller configured properly per RCS' manual. I'm able to manually control the furnace from the thermostat wall display. The only problem appears that there is no RS-485 communication between the RCS controller and the M1XSP.

Short of using a serial line analyzer to troubleshoot, I don't know what to do next. Any ideas? Thanks for your help.

 

[blmxm]

I'm unable to get a RCS TR40 to communicate with the M1XSP. The M1XSP is bus enrolled and has been supporting a M1DBH without problems. M1XSP jumpers and switches are set in accordance with Elk's Installation Manual for the TR40 (i.e. Baud=000, Mode=1001;JP3=1,JP2=0;JP1=0;Address=1000). I've checked (and rechecked) the M1XSP->TR40 wiring for terminations and continuity. The TR40 powers up and the WDU communicates with the TR40 controller configured properly per RCS' manual. I'm able to manually control the furnace from the thermostat wall display. The only problem appears that there is no RS-485 communication between the RCS controller and the M1XSP.

Short of using a serial line analyzer to troubleshoot, I don't know what to do next. Any ideas? Thanks for your help.

Does the XSP have the proper firmware?
Are you sure the data address is not duplicating another unit in your system?
Did you try sample rules per the instructions?
The installation manual states you can observe the LED's on the XSP to get an idea of communication.
M1XSP Diagnostic LED indicator
Slow blink (1/2 sec.) = Normal communication with M1.
Fast flicker = Communicating with other equipment (Thermostat, Lighting Controller, PC, etc.)
No blink = No communication with M1. Unit might be unplugged or powered off.

That's all I can think of. My TR-40 gave me no problems.

 

[wuench]

I had issues too, but for the life of me I can't remember what all I did. I know for one I had to rerun my wire to my furnace to make sure I had a common, but that might have been to get the backlight to work. And doing a search a lot of people had bad units too and had to return them.

Anyway hopefully these will help (click on them to bring up bigger images)...

Elk M1XSP


RCS TR40

 

[autophil]

Thanks for your help. I used your questions as a checklist with the following results:

Does the XSP have the proper firmware?
Yes, version 1.0.42

Are you sure the data address is not duplicating another unit in your system?
Yes, the M1XSP is set to address #1, which is the only Bus Type 5 address. The only other device set to address #1 is the main keypad, but that is a Bus Type 1 address and should not conflict with Type 5 addresses.

Did you try sample rules per the instructions?
Yes, however, they do not execute ... probably because of the T01-Not Enabled message at the keypad, i.e. M1XSP not communicating with the TA40.

The installation manual states you can observe the LED's on the XSP to get an idea of communication.
M1XSP Diagnostic LED indicator
Slow blink (1/2 sec.) = Normal communication with M1.
Fast flicker = Communicating with other equipment (Thermostat, Lighting Controller, PC, etc.)
No blink = No communication with M1. Unit might be unplugged or powered off.
Yes, there is a 1/2 sec blink on the M1XSP LED during the 1st 30sec after plugging the M1XSP into the M1DBH, then a 1/2 sec, plus a short blink, that repeats kind of like a repeating "N" in Morse code. The M1XSP is connected to the M1G via a M1DBH in J6 with the terminator in J7. All other devices (keypads, M1XIN's, etc.) connected to the M1DBH are working properly.

I'm unable to get a RCS TR40 to communicate with the M1XSP. The M1XSP is bus enrolled and has been supporting a M1DBH without problems. M1XSP jumpers and switches are set in accordance with Elk's Installation Manual for the TR40 (i.e. Baud=000, Mode=1001;JP3=1,JP2=0;JP1=0;Address=1000). I've checked (and rechecked) the M1XSP->TR40 wiring for terminations and continuity. The TR40 powers up and the WDU communicates with the TR40 controller configured properly per RCS' manual. I'm able to manually control the furnace from the thermostat wall display. The only problem appears that there is no RS-485 communication between the RCS controller and the M1XSP.

Short of using a serial line analyzer to troubleshoot, I don't know what to do next. Any ideas? Thanks for your help.

Does the XSP have the proper firmware?
Are you sure the data address is not duplicating another unit in your system?
Did you try sample rules per the instructions?
The installation manual states you can observe the LED's on the XSP to get an idea of communication.
M1XSP Diagnostic LED indicator
Slow blink (1/2 sec.) = Normal communication with M1.
Fast flicker = Communicating with other equipment (Thermostat, Lighting Controller, PC, etc.)
No blink = No communication with M1. Unit might be unplugged or powered off.

That's all I can think of. My TR-40 gave me no problems.

 

[autophil]

Thanks for the help and photos. I checked your photos carefully, and I've terminated everything the same, although I'm not entirely clear how you terminated the RS485 line because it's hard to see the exact color of each wire.

Everything works properly in manual mode (i.e. programming the TA40, setting temp from the TA40 Wall Display Unit, and controlling the furnace. My problem is getting the M1G/M1XSP to recognize and communicate with the TA40 (which is the entire purpose of this upgrade!).

Thanks again for your help.

I had issues too, but for the life of me I can't remember what all I did. I know for one I had to rerun my wire to my furnace to make sure I had a common, but that might have been to get the backlight to work. And doing a search a lot of people had bad units too and had to return them.

Anyway hopefully these will help (click on them to bring up bigger images)...

Elk M1XSP


RCS TR40

 

[hiepnola]

FWIW, I had similar issues with one difference being the Elk keypad actually registering the TR40's temperature reading. I can't recall if it was actually the correct temperature reading because it was always at 70 degrees. The M1G couldn't interface with the TR40 even though the M1XSP's lights were blinking. Finally, I checked the wiring again and found the GND (black) wire was loose on the TR40 RS485 data bus. Tightened that wire and things started working.

Thanks for the help and photos. I checked your photos carefully, and I've terminated everything the same, although I'm not entirely clear how you terminated the RS485 line because it's hard to see the exact color of each wire.

Everything works properly in manual mode (i.e. programming the TA40, setting temp from the TA40 Wall Display Unit, and controlling the furnace. My problem is getting the M1G/M1XSP to recognize and communicate with the TA40 (which is the entire purpose of this upgrade!).

Thanks again for your help.

 

[jaysonc]

I also ran into communications issues with my TR40 and M1 initially. In the end it turned out to be the termination on the RS-485 bus.

Many sources on the internet state that you must terminate both ends of the RS-485 bus, but after extensive research I found that this statement has a few assumption built into it. RS-485 is designed for very long runs. If, like me, you are using short runs you may need to use a different termination strategy.

I would recommend starting with termination on only one end of your cable run. You may need to try both ends, but start with the XSP end.

Personally, my total cable run is only about 24 inches. To get reliable communication I had to remove termination from both ends.

 

[Spanky]

There should be two terminating jumpers placed at the extreme ends of the RS-485 wire run. If you are star wiring from the control to a device you must go to the device with data A and data B and return data A and data B to the control to go to the next device. The M1DBH does the wire splicing for you. Check the wiring by turning off the power and measuring the resistance across data A and data B. It should read about 65 ohms +- 10 ohms.


Devices connected to the data bus with short wire runs inside the control box generally do not need to wired in a daisy chain.

On most M1 peripheral boards there are two 4 pin headers that connect to the data bus. Elk offers an 18 inch jumper cable that allows for daisy chaining boards in the control box together with the jumper cable. I recall WO65 as the part number.

 

[bmil]

I had the same setup working great for several years. Then one day the M1 couldn't communicate any more with the TR40 (control from the thermostat still worked). Turned out that the RS-485 portion of the TR40 control unit went bad.