OA 5000 Series User Manual 3 --- 3 5
Status and Events
The OA 5000 provides a status and event reportingsystem for the GPIB
interfaces. This system informsyou of certain significant events that occur
within the OA 5000.
The OA 5000 status handling systemconsists of five 8-bit registers and two
queues. This section describes these registersand components and ex-
plains how the event handlingsystem operates.
The registers in the event handling system fall into two functional groups:
HThe Standard Event Status Register (SESR) and the Status Byte Regis-
ter (SBR) contain informationabout the status of the OA 5000. These
registers are therefore calledthe Status Registers.
HThe Device Event Status Enable Register (DESER), the Event Status
Enable Register (ESER), and the Service Request Enable Register
(SRER) determine whether selected types of events are reportedto the
Status Registers and the Event Queue. These three registers are called
the Enable Registers.

Status Registers

The Standard Event Status Register (SESR) and the Status Byte Register
(SBR) record certain types ofevents that may occur while the OA 5000 is in
use. These registers are defined by IEEE Std 488.2-1987. Refer also to
Figure 3-6 and Table3-8.
Each bit in a Status Register recordsa particular type of event, such as an
execution error orservice request. When an event of a given type occurs,
the bit that represents that type of event isset to a value of one. (You can
disable bits sothat they ignore events and remain at zero; see the Enable
Registers section onpage 3 ---37.)Reading the status registers tells you
what types of events have occurred.
The Standard Event Status Register (SESR) —The SESR, shown in
Figure 3-6, records eight typesof events that can occur within the OA 5000.
Use the *ESR? query to read the SESR register.Reading the register clears
the bits of the register sothat the register can accumulate information about
new events.
PON URQ CME EXE DDE QYE RQC OPC
76543210
Figure 3-6: The Standard Event Status Register (SESR)

Registers