Ignition and PowerLogic EGX100 through modbus RTU

Ignition is connected to a gateway PowerLogix EGX100 using modbus RTU. This gateway is connected to a PowerLogix PM710 device. The gateway can be configured through a webpage and is possible visualizing data (comming from the device) from the same webpage. The problem is not showing I can’t see the data from the device. Why is this happening?

Have you subscribed to any tags on the device? Modbus doesn’t support browsing. You need to either create SQLTags manually, or specify some ranges of tags in the address configuration for that device and then subscribe to them.

I have specified ranges in the address configuration. When I try to visualize those tags in the quick client I just can see:

Value: null
Quality: Not Connected

You’re probably specifying too large a range then. A lot of devices will “freak out” and close the connection if you address registers that don’t exist or aren’t being used.

Try addressing one register you know exists and has a valid value, manually, by creating a SQLTag.

I already did that test and I received the same results.

Time to start troubleshooting then. Look in the logs for error messages from the device.

are you able to see the device using a modbus test program? like modbus poll, or modbus scanner?
I usually start testing using one of these programs first, cause they are easy to change settings on quickly. Its especially useful when trying to pull floats because some manufacturers order the data differently from others.

I used simply modbus and I realized that I was using the wrong driver. I was using modbus RTU instead of modbus TCP. Now Ignition is reading correctly. My question is why I was not able to connect this same device to Ignition using modbus v1 but I could using modbus v2? :scratch:

I believe you were “double-converting” - your gateway strips off the TCP wrapper and reformats the message as an RTU type to send out the serial end of the gateway (I think that mainly involves the CRC, but don’t hold me to that) - so you need to communicate with the gateway as a straight Modbus TCP style device.