Red Lion Data Station Comm Problem

Hello,

I'm programming a Red Lion CSMSTRGT Modular Controller in Crimson 3.0 to read and change parameters within various temperature controllers throughout our facility. The wireless communication network is Modbus RTU (using radio transceivers) and has been working great for some time. I'm having difficulty, however, communicating with an Omega CN7800 temperature controller on the network. I can communicate with the device fine if I plug my laptop into it with a serial converter but the Red Lion cannot communicate with the device. When looking at the activity on the wireless transceiver, the CN7800 is returning requests from the Red Lion master but the CN7800 shows up as not online when using the "IsDeviceOnline()" function. I imagine my problems with the communications blocks within the Crimson database file.

If anyone has communicated with the Omega CN7800/CN7500 series controllers, any help would be much appreciated.

First rule of serial communication check all comms. settings (Baud rate, parity, stop, etc) I bet you find something different in the settings from the computer and redlion.

The 'Ping Holding Register' has gotten me a few times on the Redlion products. Is it set? Is the register really there?

Robert good call I always forget that one.

I have rechecked all of the protocol, baud, data bits, stop bits, and parity settings and haven't found any discrepancies.

I'm using the ping holding register and it is set to register 4096 which is the first holding register available within the CN7800 controller.

I thought my problem might also be with the Frame Register Limits as the CN7800 has an 8 word max for code 03 function and a 16 bit max for code 02 function. I believe these settings within the database are correct.

I'm pulling registers data from registers 404096 and 404097 in Crimson (4096 and 4097 data worked fine with my serial converter). Could my addresses be incorrect?

Did you try adding or subtracting 1 to the registers? I would try:

4095, 4096, and 4097 for the address of the first register. Modbus is classically off by one depending on hardware. Even though it worked with your PC, if the software is different, it could be any of these.

Also Crimson can do the emulator, and possibly use your PC and the same serial port to test out your design. It might require to choose a G3 panel in Crimson, but it should only take a minute or two to hack together a G3 file to use the emulator - you only need the one serial port and read a couple of tags that are placed on the screen. That would prove out your application, cutting the problem in half.