FSR IT-VCM - Manual (Page 3)

Page 3 of 16
Serial Protocol
The protocol for the IT-VCM is a pure ASCII protocol. Each serial command begins with a three
character serial request. An ASCII space character "
_ " is used between fields in the request except
for the last field that is immediately followed by a carriage return (<CR>, 0x0D). Only one space
will be accepted between the fields, any less or more spaces, or tabs will result in an error message
being returned.
After the IT-VCM responds to a controller request, it will send a prompt to the controller. The
prompt is a carriage return (0x0D), line feed (0x0A), and a right arrow character ">". The purpose
of the prompt is to keep the display legible while typing on a terminal, hyper-terminal, or controller
terminal program.
The Serial-In port is configured for 38,400 baud, 8 data bits, 1 stop bit, and no handshaking. Serial-
In configuration cannot be changed. The Serial Output baud rate can be changed via the Serial baud
rate request "SBA".
Typical RS-232 Device Interconnections
The table below details the typical hookup for RS-232 control of the IT-VCM module.
Connections for loop through applications are included.
IT-VCM