Hp 7042Xa Status Reporting - HP 70427A User Manual

HP 7042XA Status
Reporting
NOTE
Remote Programming
Command guidelines
Error messages are read-back using the System Error query and then
entering the returned value into a string variable. The following should be
considered when reading error messages.
•
DIMension the variable for ≤255 characters
•
Error messages are stored in a first-in-first-out (FIFO)
block of memory
•
Each message contains a number and a quoted string
description
•
Reading an error message removes it from memory
•
Once an event has generated an error message, any
additional, identical event will not produce any additional
error messages until the original message has been
removed from memory.
The Status Byte is an 8-bit register that can be used to alert the operator to
certain hardware conditions in the HP 7042XA. Each binary-weighted bit
corresponds to other registers or message queues that monitor specific
instrument conditions.
When a condition change occurs in any of these registers, the corresponding
bit in the Status Byte is 'asserted' (turned on), causing a service request
(SRQ) if enabled.Querying the contents of the affected status register(s)
allows you to read-back the condition that caused the service request.
Level of Information
The following information is specific to the HP 7042XA's status structures
and commands, and is not meant as a complete tutorial on status reporting
over HP-IB. For more detailed information on status reporting, refer to the
IEEE 488.1 and IEEE 488.2 standards, or the Tutorial Description of the
Hewlett-Packard Interface Bus, HP P/N 5952-0156.
Refer to the IEEE 488.2 Common Commands in chapter 12 for more
information on the commands used with the Status Byte.
7-4 HP 70427A/HP 70428A User's Guide