Series 3700 System Switch/Multimeter User's Manual
Section 6: Model 3750 Additional Information
3700S-900-01 Rev. C / July 2008
6-23
Latching values
Channels support a status/state concept. The status of a channel indicates what
conditions are present on that channel at that point in time. Examples of channel
status are:
An overload condition exists on that channel
A channel is presently matching a pre-determined match condition
The counter/totalizer channel’s count has overflowed.
To read the present status of a channel, send:
status_now = channel.getstate('1001')
If the digital I/O matches a present match value, the
status_now
value would
be
channel.IND_MATCH
.
Status latching builds on this so that the status read by
channel.getstate()
remembers what has happened. For example, status latching tracks if the
condition EVER happened since its last reset so that you know that the status
occurred but is not now present. Manipulating the status so that it either latches
or not is accomplished with the following commands:
channel.setstatelatch()
channel.resetstatelatch()
The setting of the state latch can be read using
channel.getstate()
.