Modbus RTU over TCP reading value

Hello everybody,
I want to read some energie value by using modbus rtu over tcp in ignition. Summarly, we have an energie analyzer and modbus-ethernet gateway. they are connected each other with modbus rtu and I added that gateway to the our ethernet network by giving an IP address. I can see and add that gateway to the our ignition server and I am able to see that gateway as connected.

Now I want to read a value from analyzer which is connected to that modbus-tcp gateway. To be honest, I really do not hands on experience in reading data over modbus and tcp.

in the above picture, I see the some params that are wanted from me to read.

Also, in the picture above, we see the addresses snipping from the modbus device.

So what should I enter to read for example Voltage LN1 ? I tried to enter some values to that fields but I cannot read a value yet. I will be appreciate if somebody can help me ?

yes. anybody for helping me ?

The driver uses one-based addressing by default, so try changing the address from 0 to 1.

You mention this is a Modbus gateway you’re using, which means RTU over TCP is probably the wrong driver. Usually a Modbus gateway will convert to Modbus TCP. RTU over TCP is for when you’ve put a brainless serial converter in front.


this is the capture from modbus gateway device. in modbus tunelling parameter, I saw modbus tcp-rtu. because of that I choose that modbus rtu over tcp driver. But you may be right in this regard. But now, in current situation we are thinking that, the reason why we cannot read is caused by another problem. I mean, this modbus-tcp gateway is connected our company’s local ethernet and in that local network, port 502 can be close. thats because we cannot read according to our opinion. We thought that even if we enter wrong address, we should read meaningless values. But now we cannot read anything.