Stanford Research Systems SIM918 Operating And Service Manual page 45

3.4 Commands
SHLD(?) y , z
Example:
CHOP(?) z
Example:
SYNC(?) z
Example:
FREQ?
Example:
SIM918 Precision Current Preamplifier
Shield
Set (query) the preamplifier BNC shield connection for y
BIAS 1) to z (GND 0, BIAS 1, FLOAT 2, PROG 3) .
The following combinations are valid:
BNC y Shield z
INPUT GND
BIAS
PROG
BIAS GND
FLOAT
SHLD INPUT,BIAS
SHLD BIAS,FLOAT
Autozero
Set (query) the preamplifier autozero selection to z
There will be a wait before the chosen regime takes e ect (Sec-
tion 1.2.2.1).
CHOP?
ON
Reference Clock Direction
Set (query) the direction of the signal at the SIM918 rear-panel
Ref Clock Sync connector to z
reset to IN upon power-on.
SYNC 1
Reference Clock Frequency
Query the reference clock frequency of the preamplifier, in hertz.
The nominal frequency of the internal reference clock is 1.0 Hz. The
command can also be used to measure the frequency of an external
reference clock.
If autozero is o and the reference clock is internal, or if autozero is
o and APLL is set to OFF under external reference clock, there are no
reference clock transitions inside the SIM918 and FREQ? will time
out with Execution Error 16.
FREQ?
1.023
(OFF 0, ON 1) .
(IN 0, OUT 1) . The direction is
3 – 13
(INPUT 0,