Details about the implementation of the OD viewer PLcounter

As you have seen from the configuration of the plugin, we use two counter channels to perform the measurement: a first one which is counting and a second one to handle the measurement timing. These are 2 separate tasks, although the channels will be connected together. As a result, we cannot use a single DAQmx object as hardware controller.

The controller here is a dict containing two DAQmx, one of them is the “clock” and the other the “counter”. Each of them contains a single task.

• The clock channel is set up as a ClockCounter object (see the file daqmx.py for its definition).

• The counter channel is a Counter, and its timing source is the clock channel.

Continous grab or snap

By default, the grab_data function resets both the clock and the counting tasks. For a single snap, this is not an issue, but for continuous acquisition, this does not make sense, so we use the "live" parameter sent to grab_data to decide if we update the tasks or not.