How to Read and Write query in PLC by HMI (on software base)

[NImesh Sharma]

I have trying to design communication interface with LG-New Master K Series 300S plc.
I have also refer Master-K series document.
But i can't found any proper documents for communication.
How to read register from PLC?
How to write register in PLC?
please suggest me any documents or query format for same.
I got query from HMI which is already connected with PLC.
{STX}rM125D00025D{ETX}
This type of query format not explain in any documents.
please help me.

[Joe Tauser]

I looked at the brochure for the Master K 300S and I didn't see Modbus listed as a supported protocol anywhere.  Unitronics usually uses Modbus to communicate with other devices.

Do you have a link to what documentation you have?

Joe T.

[NImesh Sharma]

hello sir

Yes i have one document regarding to software base read and write query for LG master k 300s series plc.  But these document is not useful for me.

Thanks for your support.

Nimesh Sharma

pmu_comm_interface.pdf

[Joe Tauser]

This appears to be a manual for an LG touchscreen.  You are correct - there's no details on the protocol. 

But they do mention something on page 22 about the "CPU Direct" connection, which tells me a proprietary LG protocol exists.

Tell us about your hardware - do you have an LG Master PLC and you're trying to come up with an HMI for it?  Or are you trying to decipher how it talks?  

I found this sales information on the Master-K:

http://www.westshorecontrols.com/wp/wp-content/uploads/2015/08/master-K-catalogue.pdf

I'm not sure what we can do to help here.

Joe T.

 

[NImesh Sharma]

hello sir,

Finally we solve our 80% problem by peakHMI software. we connect peakHMI with lg plc for read data but we have one more problem we require 7c as a BCC.

I attach one image file can you send bcc calculation in your terms in programing language(we required BCC in programing language).  please little more help.

Thanks for your support.

NImesh Sharma