DT80 Range Schedule Information

What is a schedule?

A schedule is a group of tasks that will be performed using a common rate or trigger.

Each schedule has a binary data store file for Data and Alarms related to that schedule.

Each schedule has unique trigger settings for rate, file size, logging etc. Each schedule can be started or halted separately. A total of 13 schedules are available, 11 are general purpose, 1 is for statistical data and one is a polled (only) schedule.

Refer to the Users Manual for detailed information on schedules.

How fast can I set the schedule trigger rate?

The DT80 range loggers will accept schedule triggers down to 10mS (10T), although actual logging may not be achieved at that rate. The fastest speed that can be obtained in practice will depend on the tasks contained within that schedule and the effect of other tasks being performed by the logger, including writing to memory.

For most practical purposes a setting of 100mS (100T) for analog channels would be considered maximum rate.

It is possible to trigger continuously, which will run the schedule as fast as possible.

Note that digital channels, system channels, channel variables (CVs) and Serial Sensor channels can be scanned at higher rates than analog inputs.

How can I get the DT80 range loggers to sample faster?

By default the DT80 range loggers will sample a channel for 1 mains period (Default 50 Hz) This is controlled by parameter P11. Changing the sample mains frequency setting to a higher value will cause the DT80 range logger to sample for a shorter period of time. The maximum useful frequency is 1000 Hz.

Increasing the mains frequency will reduce the resolution of the DT80 range logger and may increase the noise component of the measured signal.

Does the DT80 range have ‘Burst Mode’?

No, the DT80 range logger is not designed for high speed logging.

Note: P62=1 leaves mux relays ON between scans which can be used to achieve maximum scanning rate possible on a single channel.

To get the best speed from the DT80;

P62=1 Leave relays on

P11=1000 set mains frequency to 1000 Hz

/k Turn off house keeping

Only read 1 channel

Use continuous sampling (do not specify a time )

How can I capture events?

Schedules can be triggered by events such as change of state for a digital input, counter, channel variable or Serial Sensor activity.

In addition the CopyD command will allow pre and post event data to be captured.

See sections on ' Use of memory' and ' Programming & Commands' for further for more details on the CopyD command.

Refer to the user manual for detailed command information.

Can I have different channels logging at different speeds?

Yes, use more than one schedule. Each schedule has unique trigger settings for rate. A total of 13 schedules are available, 11 are general purpose, 1 is for statistical data and one is a polled (only) schedule.