B&K Precision 4079 - Manual - Manual (Page 51)

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4.11.2 Service Request Enabling
Service request enabling allows the user to select which Status Byte summary messages may cause the device to actively
request service. This is achieved using the Service Request Enable Register, which is an 8-bit register whose bits correspond
to those of the STB. The RQS bit in the STB is set when a bit in the STB is set, and its corresponding bit in the service
request enable register is set.
The service request enable register is set using the *SRE common command, and read using the *SRE? common query.
4.11.3 Standard Event Status Register
The Standard Event Status Register (SESR) is defined by IEEE 488.2. It is implemented in the instrument as a byte, whose
bits have the following definitions:
Bit 0: Operation Complete (OPC). This bit is set in response to the *OPC common command being executed.
Bit 1: Request Control (RQC). Not implemented.
Bit 2: Query Error (QYE). This bit is set when either the controller is attempting to read data from the device when none is
available, or when data prepared for the controller to read has been lost.
Bit 3: Device-Specific Error (DDE). This bit is set to indicate that a device operation did not execute due to some device
condition. For example, trying to recall an uninitialized device stored setting.
Bit 4: Execution Error (EXE). This bit is set when the device could not execute a command, due to the command being outside
of its capabilities. For example, a parameter being out of range.
Bit 5: Command Error (CME). This bit is set to indicate an error in the command syntax.
Bit 6: User Request (URQ). This bit is not used.
Bit 7: Power On (PON). This bit is set when the device is powered on.
The SESR is queried using the *ESR? common query.
The SESR is paired with an enable register, the Standard Event Status Enable Register (SESER). This register enables one or
more events in the SESR to be reflected in the Status Byte ESB summary message bit. The bits of the SESER correspond to
those of the SESR. Setting a bit in the SESER enables the corresponding event to set the ESB bit when it occurs. The SESER
is set with the *ESE common command and queried with the *ESE? command query.
4.11.4 The Error Queue
The error queue is used to store codes of errors detected in the device. It is implemented as a cyclic buffer of length 10. When
the error queue is not empty, bit EVQ in the Status Byte is set. The error queue is read with either one of the following two
queries:
:SYSTEM:ERROR?
:STATUS:QUEUE:NEXT?
The first error in the queue is returned, and the queue is advanced.
4.11.5 Error Codes
The negative error codes are defined by SCPI. Positive codes are specific to the instrument.
The error message is returned in the form
<error number>,"<error description>"