Keithley 6517A User Manual

IEEE-488 Reference
3-35
3.11.12 *STB? — status byte query Read the Status Byte Register
Description The *STB? query command is used to acquire the value (in decimal) of the Status Byte Register.
The Status Byte Register is shown in Figure 3-18. The binary equivalent of the decimal value
determines which bits in the register are set.
All bits, except Bit 6, in this register are set by other event registers and queues. Bit 6 sets when
one or more enabled conditions occur.
The *STB? query command does not clear the status byte register. This register can only be
cleared by clearing the related registers and queues. Register and queue structure are explained
in paragraph 3.8.
For example, for an acquired decimal value of 48, the binary equivalent is 00110000. This bi-
nary value indicates that Bits 4 and 5 of the Status Byte Register are set.
The bits of the Status Byte Register are described as follows:
Bit 0, Measurement Status (MSB) — Set bit indicates that a measurement event has occurred.
The event can be identified by reading the Measurement Event Status Register using the :STA-
Tus:MEASurement? command (see paragraph 3.20 for details).
Bit 1 — Not used.
Bit 2, Error Available (EAV) — Set bit indicates that an error or status message is present in
the Error Queue. The message can be read using one of the following SCPI commands:
:SYSTem:ERRor?
:STATus:QUEue?
See paragraphs 3.21 and 3.20 for details.
Bit 3, Questionable Summary Bit (QSB) — Set bit indicates that a calibration error has oc-
curred.
Bit 4, Message Available (MAV) — Set bit indicates that a message is present in the Output
Queue. The message is sent to the computer when the Model 6517A is addressed to talk.
B7 B6 B5 B4 B3 B2 B1 B0
(2 ) (2 )
6
(2 )
5
(2 )
4
(2 )
3
(2 )
2
(2 )
0
32
0/1
Bit Position
Event
Decimal Weighting
Value
Value : 1 = Event Bit Set
0 = Event Bit Cleared
Events : OSB = Operation Summary Bit
MSS = Master Summary Status
RQS = Request Service
ESB = Event Summary Bit
MAV = Message Available
QSB = Questionable Summary Bit
EAV = Error Available
MSB = Measurement Summary Bit
OSB ESB MAV QSB EAV
0/1 0/1 0/1 0/1
128 16 8 4
MSS,
RQS
64
0/1
MSB
1
0/1
7
Figure 3-18
Status Byte Register

Keithley 6517A Specifications

General

Brand	Keithley
Model	6517A
Category	Measuring Instruments
Language	English