Communicating with Watlow EZ Zone PM via RS485

[julian70]

I am trying to communicate with a Watlow EZ Zone PM temperature controller using Dasylab to get the value of the temperature reading of the controller. The Watlow controller has EIA 485 Modbus RTU communication port and I have used an USB to RS 485 converter to connect the Watlow controller to my computer. The converted creates a communication port that I can select to set up the communication with the Watlow controller. After connecting the Watlow controller to the computer, I have place an RS Master module in a Dasylab worksheet and I have tried to communicate with the controller unsuccessfully.  I was wondering if someone could help me with the parameters of the RS Master module so I can communicate with the Watlow controller. I am using Dasylab version 11.00.01.

[CJ_Butler__DASYLab_Pro]

You should be using the Modbus module. The Modbus protocol is more complex than simple RS485/RS232. 

[julian70]

Thank you very much for your suggestion. I tried to use the Modbus Analog input module, set up all the interface parameters and I still can't communicate with the Watlow controller. The adress in the controller is 1 and the parameter ID to show the process value is 4001 which I placed on Register of the Modbus Analog Input module. The data type to view the process value is float R which I have selected in the Modbus Analog Input module (float). Subsequently, each time that I click on test I get a Modbus error message as per attached.

[CJ_Butler__DASYLab_Pro]

Try the Address starts at 0 setting. 

I end up trying most of the settings because it's not always clear from the manufacturer's documentation. 

[julian70]

I have tried the adress starting at 0 setting and still get the same error. Just in case the model number of the Watlow cotroller is PM8C1FJ-1CFJCAA. and attached is the Manual for this controller. 

[CJ_Butler__DASYLab_Pro]

Searching on that model number doesn't help... can you attach the manual?

[CJ_Butler__DASYLab_Pro]

What version (11.00.00, 11.00.01 or 11.00.02) are you running? 

There was a modbus fix in the SP2.

[julian70]

I am running version 11.00.02. The size of the manual is 10.7 Mb, consequently I can't attached it. Here is the link where you could download it:

http://www.watlow.com/products/Controllers/Integrated-Multi-Function-Controllers/EZ-ZONE-PM-Controll...

[CJ_Butler__DASYLab_Pro]

Try reading the MAP 1 or MAP 2 address... 

[julian70]

I have placed 360 for Map 1, Instance 1 on the register section of the Modbus Analog Input module and nothing. Similarly, I have placed 440 for Map 1 Instance 2 and Dasylab shows the same error.