Ascii interface with A&D balance

[PLChristian]

Hello all. I would like to transmit a command to an A&D balance from a L24ER PLC with a 1769-ASCii card I/O. The command I want to send to the Balance is the PRT command found in the manual. Any ideas on how to set up the string with "PRT" and how to transmit it to the balance?

 

[jholm90]

The manual indicates that PRT is the characters that need to be sent.

I would normally have three strings set up in the PLC:
- strPRT // constant with value ‘PRT’... add additional contacts for each command required
- strCRLF // constant with .data[0] =13, .data[1] =10, .Len= 2 (carriage return, line feed)
- strOut // value to be output

Rung would contain trigger bit, one shot and CONCAT joining all of the command string and the CRLF string into the strOut. Next rung would look to see if anything existed in strOut, then COP to ASCII card register OutData0. I will then wait for InData0.Data[0] to be equal to 6 (ASCII Acknowledge) then clear the strOut register. This will let you know that the command has been received and can continue.

See https://literature.rockwellautomati...ture/documents/um/1769-um012_-en-p.pdf#page45