Tektronix MSO54, Programmer'S Manual

Page: 918 / 1026

Status and Events
Table 3-1: SESR Bit Functions
Bit Function
7 (MSB) PON
Power On.
Shows that the oscilloscope was powered on.
On completion, the diagnostic self tests also set this bit.
6 URQ
User Request.
Indicates that an application event has
occurred. *See note.
5 CME
Command Error.
Shows that an error occurred while
the oscilloscope was parsing a command or query.
4 EXE
Execution Error.
Shows that an error executing a
command or query.
3 DDE
Device Error.
Shows that a device error occurred.
2 QYE
Query Error.
Either an attempt was made to read the
Output Queue when no data was present or pending, or that
data in the Output Queue was lost.
1 RQC
Request Control.
This is not used.
0 (LSB) OPC
Operation Complete.
Shows that the operation
is complete. This bit is set when all pending operations
complete following an *OPC command.
The Status Byte Register (SBR). Records whether output is available in the Output
Queue, whether the oscilloscope requests service, and whether the SESR has
recorded any events.
Use a Serial Poll or the *STB? query to read the contents of the SBR. The bits in
the SBR are set and cleared depending on the contents of the SESR, the Event
Status Enable Register (ESER), and the Output Queue. When you use a Serial
Poll to obtain the SBR, bit 6 is the RQS bit. When you use the *STB? query to
obtain the SBR, bit 6 is the MSS bit. Reading the SBR does not clear the bits.
Figure 3-2: The Status Byte Register (SBR)
Table 3-2: SBR Bit Functions
Bit Function
7 (MSB)
———— Not used.
6
RQS
Request Service.
Obtained from a serial poll. Shows
that the oscilloscope requests service from the controller.
6 MSS
Master Status Summary.
Obtained from *STB?
query. Summarizes the ESB and MAV bits in the SBR.
5 ESB
Event Status Bit.
Shows that status is enabled and
present in the SESR.
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