Stanford Research Systems DS335, User Manual

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Programming Commands 3-7
DS335 Synthesized Function Generator
Hardware Test and Calibration Commands
NOTE: These commands are primarily intended for factory calibration use and should never be needed
during normal operation. Incorrect use of some of these commands can destroy the calibration of the
DS335.
$CLK? The $CLK? command queries the DS335 for the status of its calibration
jumper. Shown below are the different status values that the DS335 can
return:
Status value Meaning
0 Calibration disabled
1 Calibration enabled
$FCL The $FCL command recalls the factory calibration bytes. This command will
generate an error if calibration is not enabled.
*TST? The *TST? common query runs the DS335 internal self-tests. After the tests
are complete the test status is returned. The status may have the following
values (see the TROUBLESHOOTING section for more details):
Status value Meaning
0 No Error.
1 CPU Error. The DS335 has detected a problem in its CPU.
2 Code Error. The DS335's ROM firmware has a checksum
error.
3 Sys RAM Error. The system RAM failed its test.
4 Cal Data Error. The DS335's calibration data has become
corrupt.
5 Unused.
6 Program Data Error. The modulation program RAM failed its
test.
7 DS335 not warmed up. At least 2 minutes must elapse
between power on and calibration.
$PRE (?) i The $PRE command sets the DS335's pre-amplifier attenuators to range i.
The integer i is the attanuation value in dB and ranges from 0 to 14 in
increments of two. Resetting the amplitude will return the attenuators to their
normal position. The $PRE? query returns the current attenuator position.
$PST (?) i The $PST command sets the DS335's post-amplifier attenuators to range i.
The integer i is the attenuation value in dB and ranges from 0 to 30 in
increments of two. Resetting the amplitude will return the attenuators to their
normal position. The $PST? query returns the current attenuator position.
$WRD (?) j{,k} The $WRD command sets the value of calibration word j to k. Parameter j
may have a value from 0 to 554, while k may range from -127 to +65535.
This command will generate an error if calibration is not enabled. NOTE: this
command will alter the calibration of the DS335. To correct the calibration
the factory calibration bytes may be recalled (see the $FCL command). The
calibration bytes cannot be altered unless the warm-up bit has been set.