Communication with PLC FX series (Mitsubishi) via Python

[spartachesko]

Hello everybody!
I found option for creating communication with Q series via python.
But can't find any tips for connecting with PLC FX series (FX5U).
I will be pleasure if you give me useful advice.

 

[lfe]

You can use Modbus TCP protocol as the author of this video

https://www.youtube.com/watch?v=IOkbXa6poSo

 

[parky]

Below is what the FX5 supports.

CC-Link IE field network Basic
・FTP Server
・SNTP client
・Web server (HTTP)
・Simple CPU communication function
・MELSOFT connection
・SLMP (3E frame)
・Socket communication
・Predefined protocol support
・MODBUS/TCP communication

 

[goghie]

For iQF (FX5U) and for iQR it is very easy. You can create your own protocol very easy. Look in manual for SLMP.

 

[congngu]

Can anyone help me to communicate between python and plc Fx3G though usb or rs422 ? I cant file any tutorial of it , thankyou

 

[lfe]

Can anyone help me to communicate between python and plc Fx3G though usb or rs422 ? I cant file any tutorial of it , thankyou

Mitsubishi never published the communication protocol of its RS422 programming port,

There are some HMI or SCADA that communicate through the programming port but they achieved it through reverse engineering, but always limited to 9600 baud since Mitsubshi later introduced a system by which only its products could communicate faster.

I even wrote my own driver, although I no longer have documentation for it.

I recommend that you attach an RS485 Modbus slave module to the PLC and use the Modbus protocol.

 

[parky]

The Mitsubishi protocol has never been published as stated by Ife, not sure about FX5 but the earlier FX3 programming port defaults to 9,600, on power up, however, what I think happens is the programming software tries the different rates & when connected forces the PLC to communicate at the rate defined in the programming software IDE, I came across this some years ago, I set up a Ethernet to 422 converter so I could connect to some FX's via out network, works well at 115kb until the plc is powered down & back up so it defaults to 9600, I did look into it & there is quite a bit of coms traffic when it connects I was going to decipher it but did not spend much time on it, so it is possible to force the plc programming port to a different setting. I believe the FX5 does not have 422 but 485 & ethernet so I assume that Ethernet is the one to use & no need to worry about forcing the baud rate.

 

[lfe]

I did try to figure it out by investigating what GXDeveloper was doing to connect at higher speeds, first it reads two D8000 registers from the PLC and just then writes other values to other D8000s, but I was never able to find out what operation(s) were done to calculate the seconds values based on the first ones.

 

[parky]

Yes, there must be some registers in the 8000 range like the ones used for the 232/422/485 BD card you can set certain modes in those for that card it is just a matter of finding out which ones & values for the programming port probably need to either decipher the codes sent to find the addresses but they are probably ones that have no specific function in the documentation section of the special registers..