Communicating with Watlow EZ Zone PM via RS485

[julian70]

Hello CJ, after trying several things I found the problem. The issue was in the setup of the com port in the Device Manager of the computer. After matching the parameters of the common port in the device manager and the interface on the Modbus Analog Input module, I press the test button and I can see the temperature reading of the Watlow controller. Now, I have another issue. When I tried to display the value of the Modbus Analog input using a digital meter I get weird numbers like 0.92E28. I was wondering if you could help me with this problem. I have attached the digital meter and the Modbus analog input settings. 

[CJ_Butler__DASYLab_Pro]

Try disabling the Big Endian setting. 

This is where I try all settings to get a valid reading. You can use the test button to preview the value. 

Floating point is two words, or four bytes. 

It wasn't clear from the Watlow documentation whether they are big or little endian, but they do say that the word order is low high. That could be L1 L2 H1 H2 which would be little endian. 

[julian70]

After a few iterations I get the right value when I press the test button. However, when I tried to display the raw data in a digital meter, it shows 0.00 or an error message. Do I need to put any module in between the modbus and the digital meter module?

[CJ_Butler__DASYLab_Pro]

Does the Digital Meter display ERR? That's not an error, it's a display error. Open the digital meter, click the options button, and add more digits to display. It defaults to 7. 

Where are you located? At this point you should be talking to someone, rather than having to wait on the Forum responses. 

[julian70]

I am located  in Aurora, Ontario, Canada

[CJ_Butler__DASYLab_Pro]

Call into Measurement Computing. Press 2. Tell them that you've been talking to CJ.