Specifications

Section 9. Program Control Instructions
9-21
BeginProg
Scan (1,Sec,3,0)
Timer (1,uSec,2)
PanelTemp (Ptemp,250)
TCDiff(TCTemp,1,mV20,1,TypeT,PTemp,True,0,250,1.0,0)
Elapsed = Timer (1,uSec,4)
calltable (Test)
NextScan
EndProg
WaitDigTrig (Port, Edge)
The WaitDigTrig instruction can be executed within a Scan/NextScan
sequence or it can be executed outside a scan (most commonly in a
SlowSequence).
When used inside a scan, execution of the scan is paused until WaitDigTrig is
true (that is, the specified control port rises or falls). When the scan starts, the
time stamp will be incremented by the interval specified by the Scan
instruction. This allows a clock source other than the datalogger’s internal
clock to control the timing of the measurements. This outside clock source
could be a GPS clock or the clock of another “master” datalogger where a
logic level line is connected from the clock source to one of the control ports
on the datalogger.
When used outside a scan, WaitDigTrig behaves similarly to a Delay
instruction, though the delay is based on the rising or falling edge of a control
port instead of based on time. In this instance, the WaitDigTrig instruction can
be placed inside an infinite Do/Loop, and the remaining instructions in that
loop will be performed only when WaitDigTrig is true.
The priority for performing the tasks triggered by this instruction will differ
depending upon whether the datalogger is executing its program in pipeline
mode or sequential mode. Refer to section OV 2.3 for additional information.
Note: If the program is running in sequential mode and has a slow sequence
that includes a WaitDigTrig instruction, once triggered, that sequence will not
be able to perform any measurement tasks when the main scan is running. The
slow sequence will pause before its first measurement instruction, until the
main scan is completed, after which it will continue. If the slow sequence
contains only processing tasks, these tasks can run in conjunction with the
main scan.
While…Wend
The While…Wend instructions are used to executes a series of statements in a
loop as long as a given condition is true.
Syntax
While Condition
[StatementBlock]
Wend