UM-0085-B09
DT80 Range User Manual
Page 58
RG
Insufficient Statistical Samples
If no statistical data has been scanned before being reported, then the reported data value will be set to NotYetSet. This
will also occur if insufficient samples have been taken – for example, the standard deviation (
SD
) option requires at least
two samples to be able to return a value.
This condition may occur when
•
the statistical sub-schedule is event-triggered
•
the statistical sub-schedule has been halted
•
a statistical sub-schedule scan interval is longer than its statistical report scan interval
When using statistical channel options you need to ensure that the statistical and report schedule triggers are selected
such that sufficient statistical samples are taken between each execution of the report schedule.
Example — Statistical Report Schedule
The command
RS10S RA1H 1TT 2TT(AV)(MX)
sets the statistical sub-schedule’s scan rate to 10 seconds (
RS10S
).
The main report schedule returns three temperature readings: a spot reading of channel 1 each hour (
RA1H 1TT
), and
the average and maximum over the hour from 10-second samplings of channel 2.
Working with Schedules
Entering Schedules into the DT80 (BEGIN–END)
Report schedules must be entered into (that is, sent to) the DT80 as a group. Since the schedules and processes that
comprise a job or program often extend over more than one line, you normally enclose them between the keywords
BEGIN and END to designate the beginning and end of the group. Here’s an example:
BEGIN"walrus"
1DSO=1
3CV(W)=2
RA10S
4TT("Oven Temp")
5TT("Flue Temp")
RB1S
2C("Water Flow")
END
A group of schedules such as this is called a job. In the above example, the job has been named
"walrus"
and
comprises two report schedules,
RA
(which measures two thermocouples every 10 seconds) and
RB
(which measures a
counter once a second). Note also the two "immediate" channels (
1DSO
and
3CV
) which are not part of any schedule.
These are executed once only, when the job is entered.
For more details on how jobs are entered and processed, see
.
Triggering and Schedule Order
When different schedules are due to trigger at the same time, the schedules execute in the order of
RA
,
RB
,
…RK
,
RX
.
When there are statistical channels in a schedule and the statistical sub-schedule is due at the same time as the report
schedule, the statistical sub-schedule runs prior to the report schedules. You cannot change this order. Channels within
schedules are sampled in the order of entry (left to right).
For example, consider the job:
BEGIN"cupcake"
RB2S 3V
RA5S 2V(AV)(SD) 1V
RS1S
END
