Diagnostics Operation Via The Gpib Interface - Tektronix 2432 Service Manual

Maintenance-2432 Service
troubleshoot an internal fault using external testing and
measuring equipment. Where possible, the Extended Diag-
nostics routines are used for looping to allow access to
them from both the front-panel EXTENDED FUNCTIONS
menu and the GPIB interface.
Jumper-initiated tests include Kernel Mode for the Sys-
tem µP and the Waveform µP, Waveform µP Bus Control
Mode, Bus Isolate Mode, System µP Chip Select test,
Resets for the System µP and the Waveform µP, a Front
Panel µP internal diagnostics test, and a Front Panel Multi-
plexer test. A description of these tests and how they are
used is included in Table 6-6, Extended Diagnostics.
Troubleshooting routines (written by a system program-
mer) that systematically exercise specific firmware or
hardware functions can be implemented via the GPIB
interface. This type of external testing provides a tool for
troubleshooting the scope that may be changed as needed
by controller programming.
Use of the Service Routines provide service personnel
with signals and procedures that enable fault isolation and
restoration of an instrument to a functional level that is
supported by the Extended Diagnostics and/or
other routines.
DIAGNOSTICS OPERATION VIA
THE GPIB INTERFACE
Operation of the GPIB interface is described in the Pro-
grammers Reference Guide supplied with this instrument.
This additional information describes use of the diagnostic
commands. Operation of any of the four Cal/Diagnostic
modes is selected by using the keywords SELFCal, EXT-
Cal, SELFDiag, or EXTDiag as arguments with the
TESTType command via a GPIB controller. The selected
TESTType will start when the EXEcute command is
received. See Appendix A of the Programmers Reference
Guide for the definition of the GPIB calibration and diag-
nostics commands.
SELF CAL
If TESTType SELFCal is selected, the Self Calibration
portion of the test sequence will run in its entirety when
the EXEcute command is received. A service request
(SRO) will be issued when the sequence is finished if the
OPC mask is on. The status byte received by the con-
troller will indicate if the test completed either with error or
with no error. See the Programmers Reference Guide for a
list of the status bytes.
6-34
If an error occurs during SELFCal, it is reported to the
controller when the ERRor? query is issued to the instru-
ment. ERRor? returns a string of error numbers (up to
nine) resulting from the last EXEcute command. These
numbers will be the highest order in the hierarchy of the
SELF CAL routine; so, to locate the exact test that failed
in the tree, the TESTNum must be set to a lower level and
the ERRor? query reissued until the lowest detection level
of the failure is reached. The ERRor? query returns O if no
errors have occurred. This method of failure location is
used for errors generated by any of the calibration or diag-
nostics sequences.
EXT CAL
The EXTCAL TESTtype allows specifying the calibra-
tion sequence (TESTNum) to be performed. The calibration
routine specified may be any steps or sub-steps of the
EXT CAL or SELF CAL routines. The user is responsible
for assuring that any externally required test equipment
has been connected and programmed and that pauses in
the procedure to make manual adjustments or equipment
changes are terminated via a menu button push or a GPIB
STEp command to advance to the next step in the
sequence. The external calibration sequence numbers to
be used as the numerical argument for TESTNum are
listed in Table 6-6 under the "Test Number" column head-
ing. The valid test numbers for Calibration are 7000 to
9300 in the table. Error handling is the same as
in SELFCal.
SELF DIAG
Invoking the TESTType SELFDiag causes execution of
the entire self-diagnostic sequence when an EXEcute com-
mand is received. Error handling is the same as
in SELFCal.
When Self Diagnostics is called via the GPIB, comple-
tion and/or failure will cause an SRO to be issued by the
instrument. The status bytes returned on a poll indicate a
successful completion or failure of the Self Diagnostics
sequence. Errors can then be queried via the GPIB and
traced to the lowest level of the Extended Diagnostics in
the same manner as from the front panel. Failure of Self
Diagnostics when run from the GPIB does not put the
instrument into the Extended Diagnostics menu as it does
when run from the front panel.
EXT DIAG
TESTType EXTDiag allows a specific TESTNum to be
selected for execution upon receiving an EXEcute com-
mand. Error handling and reporting is the same as in
SELFCal. Looping a test is done by issuing the LOOp
command prior to the EXEcute command, and the HAU
command stops the looping test.