2308-900-01 Rev. A / July 2008
Return to
Section Topics
7-15
Model 2308 Portable Device Battery/Charger Simulator User’s Manual
Section 7: Status Structure
Output queue
The output queue holds data that pertains to the normal operation of the instrument. For example,
when a query command is sent, the response message is placed in the output queue.
When data is placed in the output queue, the message available (MAV) bit in the status byte
register sets. A data message is cleared from the output queue when it is read. The output queue
is considered cleared when it is empty. An empty output queue clears the MAV bit in the status
byte register.
A message is read from the output queue by addressing the power supply to talk after the
appropriate query is sent.
The following command sequence enables the MAV bit (B4) of the status byte register set, and
then causes an SRQ:
*SRE 16
‘ Enable MAV bit of status byte to cause an SRQ.
Language specific
‘ Send a query command to supply.
Language specific
‘ Wait for an SRQ indicating ready to read.
Language specific
‘ Read the query response.
Error queue
The error queue holds error and status messages. When an error or status event occurs, a
message that defines the error/status is placed in the error queue.
When a message is placed in the error queue, the error available (EAV) bit in the status byte
register is set. An error/status message is cleared from the error queue when it is read. The error
queue is considered cleared when it is empty. An empty error queue clears the EAV bit in the
status byte register.
The error queue holds up to 10 error/status messages. The commands to read the error queue are
listed in
Table 7-7
. When you read a single message in the error queue, the “oldest” message is
read and then removed from the queue. If the queue becomes full, the message “350, ‘queue
overflow’” will occupy the last memory location. On power-up, the error queue is empty. When
empty, the message “0, No Error” is placed in the queue.
Messages in the error queue are preceded by a code number. Negative (-) numbers are used for
SCPI-defined messages, and positive (+) numbers are used for messages defined by Keithley
Instruments. The messages are listed in
Appendix A
.
On power-up, all error messages are enabled and will go into the error queue as they occur. Status
messages are not enabled and will not go into the queue. As listed in
Table 7-7
, there are
commands to enable and/or disable messages. For these commands, the <list> parameter is used
to specify which messages to enable or disable. The messages are specified by their codes. The
following examples show various forms for using the <list> parameter.
<list>
= (-110)
Single message
= (-110:-222)
Range of messages (-110 through -222)
= (-110:-222, -220)
Range entry and single entry (separated by a comma)
When you enable messages, messages not specified in the list are disabled. When you disable
messages, each listed message is removed from the enabled list.
NOTE
To prevent all messages from entering the error queue, send the enable
command along with the null list parameter as follows:
STATus:QUEue:ENABle ()
.
Summary of Contents for 2308
Page 2: ......
Page 12: ...This page left blank intentionally...
Page 32: ...This page left blank intentionally...
Page 106: ...This page left blank intentionally...
Page 140: ...This page left blank intentionally...
Page 208: ...This page left blank intentionally...
Page 220: ...This page left blank intentionally...