WireBiter665 (Customer) asked a question.
I have done very little work with Field I/O but my current project could benefit from using it. I have a Productivity 2000 P2-550 PLC with an EA9-T10WCL at the main station and an EA9-T6CL-R that will be located remotely from the main system for some simple user interface. I also would like to add a few indicator lights (beacons) to alert the operators near the remote station to certain conditions. I was going to use what I have on hand which is that HMI and a Protos PX-MOD Field I/O with appropriate I/O modules and run twisted pair to use RS-485. From what I'm reading, the PX-MOD wants to act as the server to the PLC client and since the HMI will also want to act as the "master" to the PLC, is this possible?
Another question along the same lines...same project but using a PX-TCP2 via ethernet and connecting port 2 to the HMI. Is this possible?
If neither of those methods will work, could I use an ethernet switch at the remote location in order to connect both units?
If none of that will work, does anyone have any suggestions?
Hi WireBiter665,
The PX-MOD is a Modbus RTU/ASCII Slave Bus Coupler. The HMI (EA9-T6CL-R) could act as the Modbus Master to this through the RS485 connection. You could then use the Ethernet port on the HMI to communicate back to the PLC for information.
Using a PX-TCP2 would just change the communication to Ethernet. The HMI driver to it would be Modbus TCP instead of Modbus Serial.
I hope this helps you out.
Regards,
Garry
https://accautomation.ca/series/c-more-hmi-series-panel/
Thank you, Garry.
I'm starting to wonder if I asked the question properly or maybe I'm not experienced enough to grasp what you're saying. I did misread about the PX-MOD being a slave instead of a server. My bad. But just to make sure, I'll try to explain better where my concerns are...
P2-550 going to a EA9-T10WCL via RS-232 and the RJ-12 port.
Remote EA9-T6CL-R on the RS-485 terminal.
All that works beautifully. Near the remote HMI, I would like to add in the PX-MOD on the same RS-485 bus. Would I still be able to control the I/O on the PX-MOD from the P2-550 considering that the P2 would be slaved to the remote HMI? I thought you could only have one master on a Modbus but multiple slaves. Or am I overthinking this? Can a slave device control another slave device?
I'll try testing it out to see how it works. Unfortunately I got pulled from that project to work on another, higher priority project. I'm fairly confident, though, that I'll get pulled from the higher priority job before completion and put back onto this one.
Again, thank you for responding.
I would use a PX-TCP1 plug into unmanaged switch then run back to P2-550 and plug into Remote I/O (External).
https://www.automationdirect.com/pn/PX-TCP1
Then you can read the Protos X coupler in the hardware configuration and it will act as remote I/O.
Refer to help topic P200 "configuration of Protos X" will help get you up an running.
+1
Hi WireBiter665
If your C-More was a EA9-T6CL instead of a EA9-T6CL-R it would have an Ethernet port that you could then connect to your network. You would then add the PX-MOD as another Modbus Slave.
Using the PX-TCP1 Ethernet (Modbus TCP) back to the P2-550 would be the easiest method.
Regards,
Garry
Thank you both for the responses. I'll take inventory of what I have available, order what I need, then try the suggestions. I was initially trying to avoid running the Ethernet if I didn't have to but the more I think about it, it's probably better if I do.
Thank you. Your help is much appreciated.
I had a little time to set this up in my test area to try it out. Final solution is: I'll keep the HMI on the RS-485 and put the Field I/O on Modbus TCP via Ethernet.
Having them both on RS-485 and using Modbus Read/Write instructions works...kind of. There seem to be a lot of data collisions and the delay is anywhere from a few seconds to a few minutes. A few seconds wouldn't matter but the average delay is much longer than acceptable for the program.
Thank you both for your responses.