HP 8921A Programmer's Manual page 218

Common Command Descriptions
*TST? (Self-Test Query)
Table 16
218
The *TST? self-test query causes the Test Set to execute a series of internal self-
tests and place a numeric response into the Output Queue indicating whether or
not the Test Set completed the self-test without any detected errors. The response
data is obtained by reading the Output Queue into a numeric variable, real or
integer. Upon successful completion of the self-test the Test Set settings are
restored to their values prior to receipt of the *TST? command. The numeric
response definition is as shown in
Self-Test Response
Detected Error
None (all self-tests passed)
68000 Processor Failure
ROM Checksum Failure
Standard Non-Volatile System RAM Failure
Optional Non-Volatile System RAM Failure
6840 Timer Chip Failure
Real-time Clock Chip Failure
Keyboard Failure (stuck key)
RS-232 Chip (I/O option installed and not
functioning correctly)
Serial Bus Communications Failure with a
Standard Board
Signaling Board Self-Test Failure
CRT Controller Self-Test Failure
Miscellaneous Hardware Failure
Refer to the Test Set's Assemlby Level Repair manual for further informaton on Power-
Up Self Test Failure.
Example BASIC program
10 INTEGER Slf_tst_respons20 OUTPUT 714;"*TST?"
30 ENTER 714;Slf_tst_respons
40 PRINT Slf_tst_respons$
50 END
Example response
512
.
table 16
Returned
Error
Code
(Decimal)
0
2
4
8
16
32
64
128
256
512
1024
2048
4096
Error Code Displayed
on Test Set's CRT
(Hexadecimal)
0000
0002
0004
0008
0010
0020
0040
0080
0010
0200
0400
0800
1000