Cable Discharge - Keithley 2790 User Manual

Model 2790 SourceMeter
Test procedure
Perform the steps in
Table 5-5
Test procedure – V-source readback
Test Step
1) Reset 2790 and
open all channels.
2) Close channels to
connect V-source.
3) Verify channels
that are closed
(optional).
4) Perform
measurement.
5) Open all channels.
Test step notes:
1. Resetting the 2790 opens all channels and selects the DCV function (auto range). For remote programming, *RST places the
2790 in the one-shot trigger mode. For front panel operation, FACT defaults places the 2790 in the continuous trigger mode.
2. This step closes the channels to connect the V-source output to the DMM of the Model 2790.
3. This step is optional. Use it to verify that the correct channels are closed for the test.
4. For remote programming, READ? triggers and requests a single reading.
5. Always open all channels at the beginning and end of a test.

Cable discharge

After using the V-source of the 7751/7753 module, a charge may be stored in the test
cables and module signal paths. The resulting voltage could ignite the inflator if it is con-
nected across a bridgewire. Therefore, a cable discharge circuit is used to safely dissipate
the charge.
In brief, cable discharge is automatically implemented when the OPEN:ALL operation is
performed. As long as the test cables are connected to the module, and the input channels
(i.e., channels 1 and 2) are closed, all stored energy in the circuit will dissipate safely.
NOTE
NOTE
NOTE
®
Switch System User's Manual
Table 5-5
Command Sequence
*RST
ROUT:MULT:CLOS (@113,118,121,
122,123)
ROUT:MULT:CLOS?
READ?
ROUT:OPEN:ALL
Details on the cable discharge circuit are provided in
The test procedure for HIPOT uses the OPEN:ALL operation to perform cable
discharge (see steps 7 and 11 in
For high ohms measurements (>1G Ω ), it is recommended that the DUT be con-
nected between two different banks (for example, Bank 1 and Bank 3 as seen in
test connection figures) to reduce the possibility of measurement errors caused
by leakage resistance.
to verify the open-circuit output of the V-source.
Press SHIFT > press SETUP > select
RESTORE: FACT.
Press CLOSE > select MULTI > select 113
> select 118 > select 121 > select 122 >
select 123 > press EXIT.
Press SHIFT > press CARD > select VIEW
> select SLOT1: 7751 or 7753. Press EXIT
when finished.
Take reading from display.
Press OPEN > select ALL.
Table 5-6).
Front Panel Operation
Section 2.
5-23