I'm having this problem with my Modbus TCP master program: a successful connection is made to the server, to be used to read a number of input registers in sequence by using the ModbusFB.ClientRequestReadInputRegisters function block. But although the xExecute input is being controlled by a clock signal which turns it ON and OFF cyclically, no ModbusTCP request has ever been sent onto the physical ethernet medium. At the same time, I get no Error or Exception messages from any ModbusTCP function...
I'm having this problem with my Modbus TCP master program: a successful connection is made to the server, to be used to read a number of input registers in sequence by using the ModbusFB.ClientRequestReadInputRegisters function block. But although the xExecute input is being controlled by a clock signal which turns it ON and OFF cyclically, no ModbusTCP request has ever been sent onto the physical ethernet medium. At the same time, I get no Error or Exception messages from any ModbusTCP function...
From the example program for ModbusTCP // Configure the MODBUS TCP client client(aIPaddr:=server.aIPaddr, udiLogOptions:=(ModbusFB.LoggingOptions.ClientConnectDisconnect OR ModbusFB.LoggingOptions.ClientReceivedValidReplies)); // Try to connect the client client(xConnect:=TRUE); After configuring and connecting the MBTCP client instance as shown, wouldn't a line like the following re-initialize the client object and terminate the connection? ...because it has just been stripped of the server's IP...
It's my very first time with Modbus but I have worked with some other networking protocols before and programmed PLCs using all of Structured Text, FBD, and LAD. I have this ModbusTCP code to read the input registers of a connected device. The problem is that the request messages are not being sent (Wireshark does not record any traffic) even though the xExecute input of the ClientRequestReadInputRegisters function block is changing as I desire when the clientTCP object is connected. I have also...
It's my very first time with Modbus but I have worked with some other networking protocols before and programmed PLCs using all of Structured Text, FBD, and LAD. I have this ModbusTCP code to read the input registers of a connected device. The problem is that the request messages are not being sent (Wireshark does not record any traffic) even though the xExecute input of the ClientRequestReadInputRegisters function block is changis as I desire when the clientTCP object is connected. I have also adjusted...