RS485 communication with Mayekawa CP IV with V1210

[Jeff-Sayto]

Hi everyone.
I have tried to communicate with a MYCOM compressor that has a MAYEKAWA controller which in the manual says that it allows RS485 communication, I have been trying for 3 days without success.
The MAYEKAWA controller detects the requests made by the V1210 but when returning the information it arrives with a 5 in the message status.

[Joe Tauser]

RS485 describes a hardware and wiring standard.  Unitronics typically uses this to send Modbus protocol commands.  Your controller must have Modbus capability for this to work.  

Can you post a link to your controller manual?

Joe T.

[Jeff-Sayto]

Hi Joe T, thanks for your quick response.

 

The MAYEKAWA processor manual link is here https://qdoc.tips/cp4-mycom-manual-pdf-free.html.

According to the document, it is possible, but I get an error when doing the holding registers.

[kratmel]

Hi, i do not find full manual, but as i know - you must use correct wiring (four wire half duplex used) for MODBUS communication and set correct communication channel in panel setup menu.

I find modbus manual for new type of panels

https://mayekawa.com/americas/mna/downloads/pdf/CP Integration/MYPRO Touchplus/DEVICELISTMYPROTOUCHAREA.pdf

https://mayekawa.com/americas/mna/downloads/pdf/CP Integration/MYPRO Touch/MYPROTOUCHDeviceListMYPROTouchAreaManual.pdf

but you must use appropriate for your panel. 

 

[AlexUT]

I found full manual.

*It is not real file name. Original file name being very complex.

Hope it will be helpful.

B.R.

 

Mayekava MYPRO-CPIV_Manual-pdf-free.pdf

[Ausman]

The manual makes reference to onboard termination resistors which I assume are set ok, and are also done correctly at the plc end.

I've said it before and will say it again, it is so much easier to do initial modbus work with the PC, to ascertain correct numbering requests and all possibilities available.  Don't forget Visilogic's numbering system can differ by 1.

cheers, Aus

[Jeff-Sayto]

Hello, thank you very much for your prompt response Gentlemen.
I want to thank AlexUT for providing the correct MAYEKAWA CP IV controller manual.
According to wiring it should be like the first image:

The data flow should be as follows but I am not very clear about this form of data flow, could you explain to me how to do it?

 

The number references should be the following, but I have called them decimal or hexadecimal but without success.

If you want to see the manual I will leave it here, again thanking AlexUT.

488091769_MayekavaMYPRO-CPIV_Manual-pdf-free.pdf

[Jeff-Sayto]

Hi Ausman, Sorry for the mishandling of the page I did not want to report your comment.
I reported it without realizing it, I'm very sorry.

I was asking him how to do the communication work first on the PC.

 

Sorry mr Ausman😔

[Ausman]

No worries at all.  I'm suggesting you use something like Modbus Poll or a similar program, which lets you easily communicate with the remote device to find what works and what doesn't.  Once you find exactly the best way to do things by using the PC, you can easily translate that method(s) into PLC use.  Trying to do it in the first place just using the PLC is very cumbersome.

Am I correct in assuming that you now have comms working ok, but are having trouble with the data layout?

cheers, Aus