Giga-tronics 8502A - Commands for Retrieving Data from the PPM

3.3.4 Commands for Retrieving Data From the PPM
UPDC Select Update Data Continuously Mode. The PPM will output a continuous stream
of power measurement data points separated by commas. Every time the PPM
receives a trigger a new data point is added to the stream. The formats discussed in
A and B below can then occur:
A. When using the FREQ, CALA (A Cal Factor), CALB (B Cal Factor), or FPRV (Rear Panel
Frequency Input) methods for detector frequency response correction (NOT FPVO), the PPM’s Linear
Mode data output string for Channel A will be:
PWRAnn.nnEsnn,PWRAnn.nnEsnn,PWRAnn.nnEsnn
(n = linear power in watts; Esnn = exponent)
This example shows a data string for 3 triggers. Subsequent triggers will produce more data points
separated by commas in the form of PWRAnn.nnEsnn. If channel B is in use, the header before the data
points would be PWRB instead of PWRA.
The PPM’s dBm mode data output string for channel A will be:
DBMAsnnn.nn,DBMAsnnn.nn,DBMAsnnn.nn
(s = polarity; n = dBm)
This example shows a data string for 3 triggers. Subsequent triggers will produce more data points
separated by commas in the form of DBMAnn.nnEsnn. If channel B is in use, the header before the data
points would be DBMB instead of DBMA.
B. When using the FPVO (Rear Panel Frequency Input and Frequency Output) method for detector
frequency response correction, the PPM’s Linear Mode data output string for Channel A will be in
the following form:
PWRAmm.mmEsee,FRQAfff.ffE+09,PWRAnn.nnEsee,FRQAggg.ggE+09
(m = first power data point;
f = first frequency data point;
n = second power data point;
g = second frequency data point;
Esee = exponent for power in watts;
E+09 indicates frequency is in GHz.)
This example shows a data string for 2 triggers. Subsequent triggers will produce more data points
separated by commas in the form of PWRAnn.nnEsnn,FRQAfff.ffE+09. If Channel B is being used, the
headers before the data points would be PWRB and FRQB. See above for a description of dBm header
and data formats.
UPDT Select Update Data Trigger Reset Output Mode. Prepares the PPM for power
measurement data taking routines using UPDN.
UPDN Update Data Now. Take a power reading when the next trigger occurs. This
command is only operational if the PPM is in the Update Trigger Reset Mode. See
UPDT.
The PPM will output a single data point each time UPDN is received. The output formats are the same as
those described under UPDC. If FPVO is being used, the frequency at which the power measurement was
taken is also output. See UPDC and FPVO.
Remote Operation
Manual No. 20790, Rev C, November 1998
3-23