VXI VT1422A - Manual (Page 110)

108 Programming the VT1422A for Data Acquisition and Control Chapter 4
Setting Filter
Cutoff Frequency
The commands for programmable filters are:
INPut:FILTer[:LPASs]:FREQuency <cutoff_freq>,(@<ch_list>)
to select cutoff frequency
INPut:FILTer[:LPASs][:STATe] ON | OFF,(@<ch_list>)
to enable or disable input filtering
Note: For the VT1529A/B, these commands affect an 8-channel bank.
The cutoff frequency selections provided by the SCP can be assigned to
any channel individually or in groups. Send a separate command for each
frequency selection. For example:
To set 10 Hz cutoff for channels 0, 4, 6, and 10 through 19, send:
INP:FILT:FREQ 10,(@100,104,106,110:119)
To set 10 Hz cutoff for channels 0 through 15 and 100 Hz cutoff for channels
16 through 23, send:
INP:FILT:FREQ 10,(@100:115)
INP:FILT:FREQ 100,(@116:123)
or combine into a single command message:
INP:FILT:FREQ 10,(@100:115);FREQ 100,(@116:123)
By default (after *RST or at power-on) the filters are enabled. To disable
or re-enable individual (or all) channels, use the INP:FILT ON | OFF,
(@<ch_list>) command. For example, to program all but a few
filters on, send:
INP:FILT:STAT ON,(@100:163)
all channel’s filters on (same as
at *RST)
INP:FILT:STAT OFF,(@100,123,146,163)
only channels 0, 23, 46, and 63
OFF
Setting the VT1505A
Current Source SCP and
VT1518A Resistance
Measurement SCP
The Current Source and Resistance Measurement SCPs supply excitation
current for resistance type measurements. These include resistance and
temperature measurements using resistance temperature sensors.
The commands to control Current Source SCPs are:
OUTPut:CURRent:AMPLitude <amplitude>,(@<ch_list>)
OUTPut:CURRent[:STATe] <enable>
•
The <amplitude> parameter sets the current output level. It is
specified in units of amps dc and for the VT1505A/18A SCP can take
on the values 30e-6 (or MIN) and 488e-6 (or MAX). Select 488 µA for
measuring resistances of less than 8,000
Ω. Select 30 µA for
resistances of 8,000
Ω and above.
•
The <ch_list> parameter specifies the Current Source SCP channels
that will be set.