76
4.13.4 Arbitrary Subsystem
The Arbitrary subsystem is not part of the SCPI standard. It was developed to suit the needs of the instrument.
Within this subsystem are commands to:
1) control the point rate, start address, wavelength, marker address, and synchronization pulse address;
2) set values of the arbitrary waveform, either discretely or using predefined, copy or draw functions;
3) protect an area of waveform memory;
4) set the state of the automatic update and increment features;
5) update the waveform.
The following shows the structure of the ARBitrary subsystem:
:ARBitrary
:PRATe <numeric value>
:ADDRess <numeric value>
:DATA <numeric value>|<arbitrary block>
:DRAW <numeric value>,<numeric value>
:CLEar <numeric value>,<numeric value>
:COPY <NRf>,<NRf>,<NRf>
:PROTect
[:RANGe] <numeric value>,<numeric value>
:STATe <Boolean>
:PREDefined <shape>,<start address>,<length>,<scale>
:STARt <numeric value>
:LENGth <numeric value>
:MARKer
[:ADDRess] <numeric value>
:STATe <Boolean>
:LENGth <numeric value>
:SAVe
Note: For model 4079, nothing changes in the commands above to control channel 1. But for channel 2,
change :ARB to :ARB2. For example, to change channel 2 to ARB mode with a predefined square wave
from address 1 with length of 2000 and scale factor of 50%, first send the command for channel to go
into arbitrary waveform mode (SOUR2:FUNC ARB), then send the command: ARB2:PRED
SQU,1,2000,50 .
When sending or receiving large waveforms with any software or custom programmed applications,
please allow AT LEAST 15 seconds or more after the process is completed on the PC before pressing any
front panel keys to return to local mode. The instrument requires this extra time to completely receive or
send the waveform.
4.13.4.1 Point Rate
ARBitrary:PRATe <point rate>
This command is used to set the point rate. It is coupled with the frequency of the waveform by the relation:
Frequency = 1/(Point Rate * Wavelength)
Thus changing the point rate will result in a change in frequency.
Arguments
Type:
Numeric