Sequoia / Tahoe Series User Manual California Instruments
M447352-01 REV-A 285
Reprogram the calibration phase with the same value obtain from the phase meter with the
command CAL:PHASE < numeric value >. You may have to add or subtract 0.2 degree to obtain
a phase meter reading of a value near zero.
7. Repeat Step-5 for output frequencies in the Master unit of 100 Hz, 200 Hz, 550 Hz, 819 Hz, and
905 Hz (with SCPI command, FREQ <n>), or the highest frequency of the particular power source
model being aligned.
8. The calibration coefficients could be verified with the SCPI query, CAL:PHASE?. First cycle the
AC input power off then on, and then send the command, CAL:PHASE?. The command will return
a command-separated number sequence of calibration coefficients with the following format:
f1,data1,f2,data2,f3,data3,f4,data4,f5,data5,f6,data6,current-cal.
9. Send the SCPI command, INST:NSEL 3, and repeat Step-6 through Step-8 to align Phase-C.
10. Reset Phase-B to 240°, Phase-C to 120º, and Phase-A to 0° with the following SCPI commands:
INST:NSEL 2
PHASE 240
INST:NSEL 3
PHASE 120
INST:NSEL 1
PHASE 0.
9.2.22 Alignment of External Programming Signal for Output Voltage Waveform/Amplitude
The external analog programming signals for setting the output voltage waveform/amplitude are available
in the External Analog Control signal connector: Phase-A signal input at Pin-1; Phase-B signal input at
Pin-2; Phase-C signal input at Pin-3; signal return at Pin-4 (refer to Section 3.8.4). The signal inputs have
a dual function, and for this alignment is selected for waveform/amplitude programming using the SCPI
command, VOLT:REF EXT. The alignment is performed with a sine wave input: for example, a 0-10 V(PK)
signal, which has an RMS range of 0-7.07 V(RMS), would produce an output voltage that would vary from
zero to full-scale of the selected output voltage range.
1. Connect the signal inputs for Phase-A (Pin-1), Phase-B (Pin-2), and Phase-C (Pin-3) together for
connection to the same function generator output in Step-2.
2. Connect a function generator to External Analog Control signal connector signals at Pin-1/Pin-
2/Pin-3 (signal) and Pin-4 (signal return); refer to Section 3.8.4Set up the function generator to
produce a sine wave output and set the output initially to zero.
3. Send the following SCPI commands to the power source (333 VAC range selected; ALC off; do
not turn on the output at this time):
OUTP 0
MODE AC
VOLT:RANG 333
FREQ 60
VOLT:ALC OFF
VOLT:REF EXT
4. Enter the calibration password with the SCPI command, CAL:PASS “5000”.
5. DC Offset alignment, high-range AC output (333 VAC):
6. Send the SCPI command, INST:NSEL 1, to select Phase-A.
To Next Page
Loading...
