I have this setup:
FX3G CPU connected to GT2103 through RS422 (CH1).
GT2103's ethernet port connected to LAN and set up as modbus TCP slave (CH2).
I want to read/write PLC word devices using a modbus TCP client, from a PC. The HMI is acting as a gateway between PLC and PC.
I used the Device Data Transfer function to send PLC's D register values to GT's internal GD registers. D0....D9 ==> GD0....GD9
After some tries, I get valid response from the modbus slave. Reading the holding registers 0....9 (40001....40009), I get only zero values.
Those registers can be written back with different values, correctly.
I'm sure I didn't understand correctly the modbus address mapping to GT's internal memory.
Can anybody help me?
Thank you.
