HP 8642A Operation And Calibration Manual

Model 8642A/B
Operation
..
You can read only the first Parameters Changed message if mure than one of each of these
has occurred since either the Status Byte was cleared or since the last time "OC" was
executed. Then reading a message using "OC''' will enable you to read out only the first
Parameters Changed message.
Following is a programming example in BASIC for outputting an ExecntIOn Error (OE):
Output clthcr all ExecutlOn Error code number or message string from the Signal
Generator (address 19) and reset bit 2 of the Status Byte:
To output the message code number:
10 OUTPUT 719; "OE"
20 ENTER 719; A
To output the message string:
10 OllTPliT 719; "OE"
20 ENTER 719; A
30 ENTER 719; A$
Dummy read of the llH'Ssage code number
The above examples can alsv ve modified to apply to an Output Parameters Changed (OC)
message
if you send "OC" instead of "OE". Sending either "OE" or "OC" alone (program line
I 0 above) will reset
the appropriate status bit (unless RQS is true, in which case the Status
Byte must be read again to clear the status bit)
Note that you should not execute an instrument function between setting up the
instrument for data output and reading the data from the Signal Generator. To illustrate
this consideration, refer to the "OE" example above. If you were to insert a line I 5 that set
an instrument function such as AM, the data received from the Signal Generator will be
the display data, not the Execution Error message code, because "AM" would have
superceded the "OE" data output preparation.
Hardware Errors
Hardware Error messages are handled differently than Execution Error or Parameters
Changed messages since more thaIl one message caIl be present. These messages are stored
as a queued up list with a maximum number of 22 messages (Read about queued up
messages Oil page 3-180). To properly retrieve all the queued up messages, follow the
"OH"
command with a software loop as shown in the sample program in Table 3-6 (page
3-23).
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HP 8642A Specifications

General

Brand	HP
Model	8642A
Category	Inverter
Language	English