'Regular' RS232 is +/-12V on the ouput pin. RS232 TTL seems a lot link RS422/485 - see below.It just threw me that they call it RS232 TTL...
Why leave the RS232 part in there?
You don't think its something like -5/+5 for high low?
by Don Wilcher
by Duane Benson
by Jeff Child
by Aaron Carman