Anritsu ML2437A - Using 488.2 GPIB; 488.2 Command Format

Using 488.2 GPIB GPIB Operation
8-6 PN: 10585-00001 Rev. P ML2437A/38A OM/PM
8-5 Using 488.2 GPIB
The IEEE 488.1 GPIB standard was updated in 1987 to 488.2 to better enforce
standardization of GPIB communication. This section explains the fundamentals of 488.2
GPIB operation and how it is implemented in the ML243xA Power Meter. Refer to the full
IEEE 488.2 standard for more detailed information.
8-6 488.2 Command Format
All commands should follow the basic format:
<MNEMONIC><white space><comma separated message parameters><terminator>
<white space> = Normally a space character, but can be any of the white space characters
listed in the 488.2 manual.
<terminator> = A line feed character (for example, \n in ‘C’ or VBLF in Visual Basic). An EOI
(End Of transmission Interrupt) can be used as the last character instead of the line feed.
Example: AVG A,MOV,64
A number of commands can be put into one program message by separating the commands
with semicolons. Example:
CHCFG 1,A;CHCFG 2,B-A;CHUNIT 1,W;CHUNIT 2,DBM;OPMD DIGIT
Status Byte
The 488.2 standard added two extra predefined bits to the status byte, these bits are the
Event Status Bit (ESB) and the Message AVailable bit (MAV).
Event Status Bit (ESB)
In 488.2 there is an event status register (ESR) that allows the state of the GPIB interface to
be monitored. All the bits in this register are defined. These bits are:
76543210
PON URQ CMD EXE DDE QYE RQC OPC
Table 8-4. Event Status Register (ESR)
Bit Description
PON Power On bit. This bit is set on power up of the device only.
URQ Not used in the ML243xA
CMD Command error. Received an illegal command.
EXE Execution error. Could not execute a command. For example, a parameter is
out of the allowable range, or requesting graph data while in readout mode.
DDE Device Dependent Error. The specific error can be found by using the
ERRLST command.
QYE Query Error.
RQC Request Control. GPIB controllers only.