GE 90-30/20/Micro Function Block Data Required for Timers and Counters, Abbreviation Function

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Section 2: Timers and Counters

This section explains how to use on-delay and stopwatch-type timers, up counters, and down counters. The data associated with these functions is retentive through power cycles.

Abbreviation	Function	Page
ONDTR	Retentive On-Delay Timer	4-11
TMR	Simple On-Delay Timer	4-14
OFDT	Off-Delay Timer	4-17
UPCTR	Up Counter	4-20
DNCTR	Down Counter	4-22

Function Block Data Required for Timers and Counters

Each timer or counter uses three words (registers) of %R memory to store the following information:

current value (CV)	word 1
preset value (PV)	word 2
control word	word 3

When you enter a timer or counter, you must enter a beginning address for these three words (registers) directly below the graphic representing the function. For example:

(enable) *ONDTR*- ONDTR(Q)- time

(reset) - R

(preset value) - PV

(address) - Enter the beginning address here. here.

Note

Do not use consecutive registers for the 3 word timer/counter blocks. Logicmaster does not check or warn you if register blocks overlap. Timers and counters will not work if you place the current value of a block on top of the preset for the previous block.

GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-9