Filter
Top Products
Digital Input Operations
The multifunction module (34907A) has two non-isolated 8-bit
input/output ports which you can use for reading digital patterns.
You can read the live status of the bits on the port or you can configure
a scan to include a digital read.
• The digital input channels are numbered “s01” (lower byte) and “s02”
(upper byte), where s represents the slot number.
• You can generate an alarm when a specific bit pattern or bit pattern
change is detected on an input channel. With the multifunction module,
the channels do not have to be part of the scan list to generate an alarm.
For more information, see “Using Alarms With the Multifunction Module”
on page 130.
• When you add a digital read to a scan list, that port is dedicated to
the scan. The instrument issues a Card Reset to make that port an
input port (the other port is not affected). While included in the scan
list, you can still perform low-level read operations on the port, but
you cannot perform write operations on the port.
• From the front panel, you can read data from only one 8-bit input
port at a time. From the remote interface, you can read both ports
simultaneously as a 16-bit word only if neither port is in the scan list.
If one or both ports are included in the scan list, you can read only
one 8-bit port at a time. However, if you have included both ports in
the scan list, the data will be read from both ports simultaneously
and will have the same time stamp. Therefore, you can externally
combine the two 8-bit quantities into a 16-bit quantity.
• From the front-panel only, you can specify whether you want to use
binary or decimal format (readings are always stored in memory in
decimal format). Once you have selected the number base, it is used
for all input or output operations on the same port.
• You can monitor a digital input channel even if the channel is not
part of the scan list (the internal
DMM is not required either).
• A Factory Reset (*RST command), Instrument Preset (SYSTem:PRESet
command), and Card Reset (SYSTem:CPON command) from the
remote interface will reconfigure both ports as input ports.
Note that a from the front panel resets only the port currently
selected (both ports are not reset).
4
Chapter 4 Features and Functions
Digital Input Operations
133