Hi folks,
I am putting together a flow to read and write 32bit floats from/to a PLC using Modbus TCP.
To be honest it took mw way longer than it should have to get my head around the buffer manipulation nodes but I have them working now and can read and right floats... Which is nice!
However if I want to change the quantity of data read I have to alter the trigger for the flex_modbus node and also adjust the lengths for both the buffer nodes.
For context my read ...
my read gets 'some', lets say 6, words from the PLC, these are 'raw' values which I treat as uint16.
This data is used to create a buffer, 12 bytes long.
The buffer is then interpreted as a float32, which is how the PLC is interpreting the same data.
Writing out is a similar process that prepares an array of two uint16 for the flex_write node.
As I said both processes work but I would ideally like to create sub flow that wrap the process in much the same way as the flex-modbus nodes work.
I have tried copying the 'length' path and setting that with a change node but couldn't get it to work.
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"failureLogEnabled": true,
"tcpHost": "192.168.10.19",
"tcpPort": "502",
"tcpType": "DEFAULT",
"serialPort": "/dev/ttyUSB",
"serialType": "RTU-BUFFERD",
"serialBaudrate": "9600",
"serialDatabits": "8",
"serialStopbits": "1",
"serialParity": "none",
"serialConnectionDelay": "100",
"serialAsciiResponseStartDelimiter": "0x3A",
"unit_id": "255",
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Thanks for looking,
Al
