touch screen via rs485

[kenobe]

I just bought a hakko V6 touch screen and I want to connect it to my T100MD888 via rs485 port. How do I initialize the communication? do I have to write a PLC program to receive and send data to the touch screen?

[support]

Does your touch screen support MODBUS protocol? If it does then all you need to do is to refere to Chapter 5 of the T100MD User Manual for Modbus memory map to the PLC's I/Os and internal memory and you can configure the touch screen to talk to the PLC. The PLC can automatically respond to MODBUS command as long as the communication settings such as baud rate etc are correct. You can also use the SETPROTOCOL command to fix the protocol to MODBUS only mode which can speed up the processor's response to MODBUS protocol.

[kenobe]

Thanks for your advise
I have one more question.
I can set the T100MD to be either Master or Slave, which one is better?
In my case, I just use the touch screen to provide some virtual buttons and display some data and plot graphs.
Am I right that I have to create a .pc6 program to react with the touch screen? how do I send data graphs to the touch screen.
Thanks

[support]

If you use the PLC as slave, then no need for any .PC6 files other than to set the baud rate to that of the same of the touch screen (or if you set the touch screen to that of the PLC, then nothing in the PLC's program need to specifically work with the touch screen). Of course you may choose to use the touch screen to change some variables (e.g. some DMs) and in your .PC6 program you can then access these variables for your program use.

If you use the PLC as master, then you need to use READMODBUS, WRITEMODBUS, READMB2 or WRITEMB2 commands to interact with the touch screen. TBASIC can easily handle that too. So the choice is yours to make.

[kenobe]

Thank you very much.
You have cleared my doubts.
Thanks