MELSEC A RS422 (25pin) <> iQR C24 Serial RS232 (9pin) - Simple PLC Communication

[jenas6423]

MELSEC A RS422 (25pin) <> iQR C24 Serial RS232 (9pin) - Simple PLC Communication

Communication from a MELSEC-A Series CPU (RS-422 – DB 25 Pin) with R Series CPU C24 Serial Module (RS-232 – DB 9 Pin).

I would like to request for support for the Wiring Diagram of the RS-232/RS-422 conversion cable. So far only Diatrend DAFXIH-CABV that works. But I couldnt find any wiring diagram for DAFXIH-CABV.

Due to high cost of DAFXIH-CABV, I am looking for alternatives, I am testing with standard RS422 <> RS232 converter in the market, but all failed to communicate, can anyone help?

Reference:
https://www.diatrend.com/IFcable/9p/dafxih-cabv.php#kanren
https://dl.mitsubishielectric.com/dl/fa/document/manual/plc/sh081251eng/sh081251engk.pdf


Page: 119 (Section 6.1)


Please advise.

Appreciate your help

 

[parky]

Just google SC09 cable pinout that gives you the pinout of the 422 & 232 but may require the 232 pins 2&3 swapping.

 

[jenas6423]

Hi @parky,

Thank you for your reply.

We have tried SC09, and it was unable to communicate between MELSEC A and C24 RS232 port with the same setting as Diatrend DAFXIH-CABV.

Do you mean we have to swap pin 2&3 for RS232 end of SC09?

Why is that and how do we do that?

Please advise.

Appreciate your help.

Thank you

 

[parky]

It was just a suggestion to build one using some other 422 unit, Swapping pins 2 &3 was just a sugestion as some equipment uses a crossover (null modem) some use strait through, used to be able to get crossover adapters but as 232 is not used much now they could be hard to find.
I built my own just back to back 9 pin connectors but wired 2 & 3 pins crossed over so you have a 9 pin plug & 9 pin socket wired pin to pin but cross over 2 & 3. I used to use it for the Beijers (Mitsubishi) HMI's as the original programming lead changed when they went from the older Mac series to the E series.

 

[jenas6423]

Hi @parky,

Thank you for your reply.

I have tried to solder a crossover RS232 cable switching both pin 2&3 and 7&8. But unfortunately, didnt get it to work as well.

Is there any other troubleshooting method we can use?

Appreciate ur advice.

Thank you.

Regards.

Jenas