User manual

Instruction Set

Counter 3-8

counter instructions continued...

Instruction Description

Count Down

CTD

Status Bits:

CU-Count Up

CD-Count Down

DN-Count Done

OV-Overflow

UN-Underflow

If the input conditions go true, counter C5:1 starts counting, decrementing by 1 every time the

rung goes from false-to-true. When the accumulated value is less than or equal to the preset

value (10), the counter resets the counter done bit.

Counter Reset

RES

If the input conditions go true, counter C5:1 is reset. This instruction resets timers and counters,

as well as control blocks.

COUNT DOWN

Counter C5:1

Preset 10

Accum 35

CTD

Rung

Condition

ACC

Value

CTD

Status

False 0000 Reset

False 0 1 0 >=preset Preload

Toggle True 1 1 0 decr by 1 Counting

True 1 0 0 <preset Done

True 1 0 1 <-32768 Underflow

C5:1

(RES)