Sending string from Inject node to Serial Out node

I am using a GRV-EPIC-PR2 with GRV-CSERI-4 to read serial data (RS-232) from an ultrasonic welder (the welder outputs a string with a line break every time a weld cycle is run).

I am also attempting to send commands to the welder over the same RS-232 line per the manual for the welder. According to the manual I can send the string ‘PS’ with a line break and the welder will ouput a specific message (the weld settings) over the same RS-232 line (I am attempting all of this while the welder is NOT in the middle of a cycle).

I was able to get the welder to respond to my messages in the debug pane, but not as expected. I received the message ‘E99 Line too long’ from the welder, which according to its manual means that I sent a string longer than 40 characters.

Based on this information I am wondering if I am using the inject and serial out nodes incorrectly and the welder serial port is receiving something other than a pure ‘PS’ string.


Probably worth noting that the welder very old so this could be an issue internal to the welder.

What does the debug tab show for the debug 5 node when you send the command?

Are you using PAC Control? Are there any serial port commands being used there?

EDIT: Have you tried \r as the ‘line break’ character?
Have you tried \r\n as the line break character?
Have you tried setting the DTF, RTS etc to ‘none’?

Does the welder respond with the E99 each and every time you send the command?