4 – 2
Performance Tests
4.1
Getting Ready
Recommended instruments include:
1. SRS SIM900 Mainframe
2. Agilent 3458A 8
1
/
2
digit multimeter
3. SRS SR620 Time interval counter
4. SRS SR785 Dynamic signal analyzer
5. PC with remote interface to SIM900 Mainframe
Also needed is a 96:1 resistive divider formed by soldering two re-
sistors, a 210.0
Ω
and a 20.00 k
Ω
resistor (both
±
0
.
1%) in series. The
resulting three conductors of this network will be labeled for future
reference as follows: The conductor running between the resistors
will be called the “center”, the conductor on the 210
Ω
end will be
the “bottom”, and the conductor on the 20 k
Ω
end will be the “top”.
This divider will be used externally to the SIM960 to test the integral
gain accuracy.
The SIM960 should be given at least one hour to warm up after power
is turned on, and care should be taken not to constrict the ventillation
holes in the SIM900 mainframe. It should be located in a room with
stable temperature, preferably from 65 to 75 degrees F.
4.2
Performance Tests
The various subsystems of the SIM960 can be tested with the fol-
lowing procedures. In all cases, if the measurement is outside the
tolerance or range indicated, then the SIM960 is out of calibration.
4.2.1
Input Amplifier Offset
Ground the two inputs, ’Setpoint’ and ’Measure’ of the SIM960 using
BNC grounding caps or 50
Ω
terminators. Using the remote interface,
reset the SIM960 using the
*RST
command. Select ’External’ by
pressing [Setpoint] on the front panel. Adjust the
P
(gain) parameter
to 1000 (maximum gain). Use the Multimeter to measure the Error
output at the rear panel BNC of the SIM960. Switch the polariy of the
P
(gain) parameter and observe the change at the rear panel Error
BNC. The readings for both polarities should be within
±
10 mV of
zero.
4.2.2
A to D Converter test
•
Reset the SIM960 using the
*RST
command.
SIM960 Analog PID Controller
