Writing Digital Data - Keysight Technologies 34950A User Manual

MEAS:DIG? BYTE, (@1102)
By adding parameters to the command, you can set the channel width, polarity,
and threshold for read. For example, sending the following SCPI command you
can read the 32-bit channel 201.
MEAS:DIG? LWOR, (@1201)
To read digital data with more control over the channel parameters, use the SCPI
CONFigure and SENSe commands. The CONFigure commands set up the digital
I/O channel parameters. For example, sending the following SCPI command to a
Digital I/O module installed in slot 1 of the mainframe, sets a 16-bit input channel
(103) to use a 2.5 V input threshold, and normal polarity.
CONF:DIG WORD, 2.5, NORM, (@1103)
Once configured, the data is read using the following command.
SENS:DIG:DATA:WORD? (@1103)
You may also read an individual bit using the SENSe commands. This allows you to
check the state of an individual bit in a channel without having to create an input
mask. For example, the following command returns the state of bit 3 in the
channel 101 byte.
SENS:DIG:DATA:BIT? 3, (@1101)
The acceptable range for the bit parameter is based on the channel width as
shown below:
– BYTE (8-bit): <bit> can range from '0' to '7'
– WORD (16-bit): <bit> can range from '0' to '15'
– LWORd (32-bit): <bit> can range from '0' to '31'
The SENSe command differs from the MEASure command in that it will not change
the direction (input or output) of the channel. If the channel is configured as an
output, the SENSe command will return the value being driven.

Writing Digital Data

To write digital data, set the channel output parameters using the SOURce
commands. For example, sending the following SCPI commands to a Digital I/O
module in slot 1 sets a 32-bit channel to use normal polarity, with active drive and
a 'set' output voltage of 4 volts.
14 Keysight 34950A User's Guide