•A command is contained in a message, and messages can contain more than one command, each one separated by a semicolon (;). For example, CLOSE 6;XDR 2 1 <CR> <LF> contains two commands.
•All GPIB commands must end with the terminating sequence <CR> <LF>.
•All RS232 commands must be terminated with a single <CR> character.
•The input buffer of the switch can hold as many as 100 characters. If the buffer becomes full, the switch holds the handshaking line on the GPIB interface until space is available. Similarly, over the RS232 interface, the switch sets the Clear To Send line low. Any characters received after the line goes low are ignored.
•Commands are executed as they are parsed; consequently, a command can be executed before the entire message in which it is contained is received.
•The switch delays accepting new characters sent over the GPIB interface while the switch mechanism is moving, but no data are lost. The SB switch is always ready to accept characters over the RS232 interface.
•A query command is used to extract status information from the switch. For example, SRE? <CR> <LF> returns the contents of the status register.
•
Operation Commands
RESET
Reset
Returns the switch to the
CLOSE i
Set Optical Channel
Closes the optical path represented by the integer i.
XDR i k
Driver Control
Sets the specified external driver on or off.
•i = driver number (1 to 8)
•k = 1 (on)
•k = 0 (off)
Programming Guide – 26
