We are trying to give the value of some variables to a client's Modbus Master using a Communication Gateway and let's call this Communication Gateway A.We had put the digital variables at the holding registers and we could not see them.I put them at the Input Registers and now the client could see their values,but he cannot see the updated variables which are in the Input Register's tab,the values are not being updated although on A,I see that the values coming from the controller are being updated every moment,but the client is not receiving the updated values through the Modbus,moreover the values that the client is seeing is are like those of some days ago when the machine was running,and when I force the variables on the controller nothing gets changed in the client's SCS

 

So you've confirmed that the values on the gateway are updating, but the values in the clients Modbus Master are not.

Since Modbus is a request/response protocol, it may be simply that the Modbus Master is not making requests to read the Input Registers from the gateway. This could be due to misconfiguration of the Modbus Master, or perhaps it could be due to a communication/connection/wiring issue.

You'll need to provide more details for additional assistance. Is this Modbus RTU or Modbus/TCP? What is the vendor and model of the communication gateway? What is the client's Modbus Master?

 

Hello,where do I see what type of Modbus do I have?

 

Are the devices connected via RS-485 or Ethernet?

If RS-485, then it's Modbus RTU (or possibly the less common Modbus ASCII).

If Ethernet, then it's Modbus/TCP.

 

Are the devices connected via RS-485 or Ethernet?

If RS-485, then it's Modbus RTU (or possibly the less common Modbus ASCII).

If Ethernet, then it's Modbus/TCP.

thanks,it was Modbus RTU,the problem was that the Raw Min,Raw Max,and Eng Min and Eng Max values were not defined well in the toolboxST