I've been fighting this one for a long time. I need to write a new subroutine for an existing program. I have the RS-232 port initialized properly, but I need to see the numeric character string come in first. If the string does not meet correct criteria (such as value(s) in range for the function), then sends out a '0', followed by a <CR> (ASCII 13). If it does, then the function needs to be performed (by other subroutines that are already defined) then sends out '1' <CR>.
Thank you for your support.