Red Lion G3 to Watlow F4 temp controller

I have a Red Lion G315C2 that I plan to use as a paperless chart recorder to monitor several tempering furnaces. Each of the furnaces use a Watlow F4S ramping temperature controller. I plan to link all of the controllers together and talk to them using Modbus RTU. Unfortunately I don't have a lot of experience using Modbus for communication.

I currently have the Red Lion G3 and a spare Watlow controller setup on my desk so that I can get it working before I try to permanently install anything.

By shear "dumb luck" I have been able to read the current temperature value but I can not read any of the other values in the controller.

Here is what I have configured to read the temperature:
- RS-485 comm port A set as Modbus Universal Master with Modbus RTU protocol
- Created a device under the protocol called "Heat_Controller"
- Created a tag referenced to the device
- Used "data item" type 4 (holding registers)
- set address as 00101, which when confirming sets the address of the tag as 400101.

While this works, unfortunately the address of the value I am trying to get is 100 not 101. I have tried creating additional tags to record other information from the temperature recorder, but I have been unsuccessful with anything else. Has anyone else tried to do anything similar to this?

Here is a link to a manual for the Watlow controller I am using. The section on communication starts on page 77 of the PDF.
http://www.watlow.com/downloads/en/manuals/f4sd_eng_g.pdf

Thanks in advance for any help anyone can provide.

From looking at the manual there appears to be a one register offset in the mapping which would explain the 100 vs 101 issue. What other items have you tried to reference?

Thanks
Jeremy

I've also tried to view which profile step number the ramp controller was in. The manual says it is parameter #4001 so you would think it should be 4002 if it is offset by one. Unfortunately that doesn't work.

When you read this register does your display show dashed lines or an incorrect number? Have you tried mapping to a register above and below what you think it should be?

Thanks
Jeremy

I think I figured out my problem. After rereading the manual again, it seems that the parameters in the 4000 range are related to the programmed profiles and I don't think they are readable. I think they are only used when writing new profiles to the device via Modbus. I tried some of the other parameters that I can find the value of on the front panel, and they do seem to be just offset by one.

Thanks for your help.

By the way, are there any program examples available using the Crimson 3.0 software? The only ones I have been able to find were programmed with Crimson 2.0.

Good to hear that you are able to read those values.

There are not any samples at this time. However you can import the existing C2 files into C3.

Thanks
Jeremy