Option 01 VXI Interface Module User Manual 4–1
Status and Events
The Status and Event Reporting System reports asynchronous events and errors
that occur in the Option 01 VXI Interface Module. This system consists of four
8-bit registers and two queues that you access through the command language.
You can use these registers and queues to query the instrument status and control
the interrupts that report events.
In general, after an interrupt occurs, first conduct a serial poll, query the registers
to see why the interrupt occurred, and then send the SYSTem:ERRor? query to
see a descriptive error message.
This section describes the four registers and two queues of the Status and Event
Reporting system. For each register, you are given a description, a table
describing all of the bits, and an example of how to use the register.
The Status and Event Reporting process, synchronizing programming com-
mands, and the system messages are also described in this section.

Status and Event Reporting System

The Status and Event Reporting system monitors and reports such events as an
error occurring or the availability of a response to a query. This system includes
descriptions of the following registers and queues:
HStatus Byte register
HService Request Enable register
HStandard Event Status register
HEvent Status Enable register
HOutput queue
HSystem Error and Event queue
The Status Byte register, shown in Table 4–1, summarizes information from
other registers. Use a serial poll or a *STB? query to read the contents of the
Status Byte register. The response is the sum of the decimal values for all bits
set. When you use a serial poll, bit 6 shows Request Service information. When
you use the *STB? query, bit 6, the Master Status Summary bit, indicates that
bits 5, 4, or 2 may be set.

Status Byte Register