Toshiba T3 PLC Computer Link <-> RS-485 (real time data extraction)

Hi everyone,

I need to interface an external PC with a Toshiba T3 CPU (model PU326H) in order to read data from several 'F' registers.

The external PC sends data via RS-232 to a RS-232 <-> RS-485 converter, then that converter sends data via RS-485 to the Toshiba T3 PLC "Computer Link" port, located on the bottom of the Toshiba T3 PLC.

The setup I have enabled so far is as follows:

Select System Parameters
Inside Computer Link Setup, choose the station (=1)
Inside Computer Link Setup / Communication Parameter choose Baud rate = 19200, Parity=None, 8 data bits, 1 stop bit

See full setup visible from here:

https://www.dropbox.com/s/uoqfj3v08c3dp6u/PM3 overview for Toshiba PLC experts.pdf?dl=0

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The problem I am having is that while I can send data via the RS-232 converter, no data is sent back from the Toshiba PLC.

Has anyone ever setup the Computer Link port on a Toshiba T3 PLC? Any clues as to what is causing the issue I am observing?

Any help is appreciated, thank you.

Regards to all members.