Hi,
i am having issues setting up my modbus configuration on PLC IDE.
i have my modbus device working (confirmed using modbuspoll and usb to rs485 adapter)but even after following various guides and videos online i cannot get any results back to my opta plc through PLC IDE.
my device has a baud rate of 115200, slave ID 1, 8 Bits, 1 stop bit and no parity.
when using modbus poll i send my command in hex and receive it back with the correct result but nothing PLC IDE.
Any more recent guides or assistance as the guides i did find seem to be a bit dated.
was considering going down rhe modbus custom editor route but cannot find much about this online
Hello, i have the same issua at the start, if you need more information, I’ve used it and haven’t had any issues.
If you're using the PLC IDE, you should start by creating a Modbus RTU client instance in the connections section.
However, I don’t really like the PLC IDE — it’s much easier to do it with Arduino. add the modbus rtu in plc ide you need to use as client if you need read from other device or server if you need read/and write : Modbus RTU On Opta™ Using PLC IDE | Arduino Documentation
You just need add the RS485 libraries in arduino ide, specify what you want to read, and send the requests to the location you need.
Hi,
i have set all of the connections up to what i think is the correct configuration based on information i found on other posts but i still was getting no response. Not even an error.
i will try arduino IDE and see if i have some more success.
Well, what you need is a Modbus client. If I'm not mistaken, some time ago I had made one with LoRa — just a bit — but for Modbus over Ethernet. The operation should be the same. I mostly used RS485 on the OPTA PLC as a server rather than a client. You can follow the example here, just like you would in Python. What you need are the baud rate, server address, connection type (8N1, 8E1, 8P1), the starting address to read from, quantity, and so on. you can see how to make a client in : Getting Started with Modbus RTU on Opta™ | Arduino Documentation