User manual

Prologix GPIB-USB Controller User Manual
9/15/2009 8
8. Commands
Prologix GPIB-USB controller provides several commands to configure its behavior.
They are explained in detail in the following sections. All commands start with the “++”
character sequence.
Commands must be terminated with CR or LF.
8.1. addr
The addr command is used to configure, or query the GPIB address. Meaning of the
GPIB address depends on the operating mode of the controller. In CONTROLLER
mode, it refers to the GPIB address of the instrument being controlled. In DEVICE
mode, it is the address of the GPIB peripheral that Prologix GPIB-USB controller is
emulating.
An optional secondary address may also be specified. Secondary address must be
separated from the primary address by a space character. Valid secondary address values
are 96 to 126 (decimal). Secondary address value of 96 corresponds to secondary GPIB
address of 0, 97 corresponds to 1, and so on. Specifying secondary address has no effect
in DEVICE mode.
If the command is issued with no parameters, the currently configured address (primary,
and secondary, if specified) is returned.
SYNTAX: ++addr [<PAD> [<SAD>]]
PAD (Primary Address) is a decimal value between 0 and 30.
SAD (Secondary Address) is a decimal value between 96 and 126. SAD is optional.
MODES AVAILABLE: CONTROLLER, DEVICE
EXAMPLES:
++addr 5 – Set primary address to 5
++addr – Query current address
++addr 9 96 – Set primary address to 9 and secondary address to 0
NOTE:
Default GPIB address of many HP-GL/2 plotters is 5.
8.2. auto
Prologix GPIB-USB controller can be configured to automatically address instruments
to talk after sending them a command in order to read their response. The feature called,