I have a FX3U-16MR/DS with 485ADP-MB + 232-BD. The 232-BD is linked to a radio modem and the 485 to frequency drive. There is also an additional IO card attached. This is my first project with mitsubishi and with modbus RTU. I'm supposed to add a couple of data to be sent over the radio modem attached to 232-BD connection but I can't figure out what it is already sending. I think the write data is to a registed D2000 which is an array and then sen't over the radio modem. But I can't for the life of me figure out where in the program something is written to the register so I could find out how much free space there is in the Array and I wouldn't be over writing something. So I'm just guessing here and indirect addressing is used but I don't understand how it is done in mitsubishi? The program has been written with IEC developper and I'm only familiar with GX works2.
Any examples or help would be much appreciated.