This is a more general form of the protocols for Gilson HPLC pumps in CO2gui and the Gilson pump files.

Create a serialObject:
serialObject = gsiocobj(comPortNumber)

Connect to the device:
gsiocobjconnect(serialObject)

Send some commands:
gsiocobjcomm(type, serialObject, deviceID, command) writes or reads information from GSIOC devices (initially designed for the 305, but probably works the same for other devices), connected via the Gilson 506C interface through RS232 (the pumps connect to the interface via RS422). type is 'read' or 'write', serialObject is the serial port object, deviceID the ID of the GSIOC device (they are set to 1 by default, but
% may be between 1 and 63 depending on the system - the interface is usually 63), command is the command to be read/written. If reading a value, function responds with the requested value. If writing a value, the response is [1 value] if successful. For both read and write operations, the response is -1 if the controller returns an unexpected message, -2 if there was no response, or -3 if any of the arguments were invalid.

Disconnect and cleanup when done:
gsiocobj(serialObject)