Bradley Smoker PLC-5 user manual Compare Instructions, Ctd, Lim, Meq

Instruction Set Quick Reference D-5

Instruction Description

CTD

COUNT DOWN

Counter C5:1

Preset10

Accum35

Count Down	If the input conditions go true, counter C5:1 starts
CTD
	counting, decrementing by 1 every time the rung goes from
	false-to-true. When the accumulated value is less than the
	preset value (10), the counter resets the counter done bit.
Status Bits:	Rung	CD	DN	UN	ACC	CTD
		14	13	11	Value	Status
CU-Count Up	Condition
CD-Count Down	False	0	0	0	0	Disabled
DN-Count Down done
	False	0	1	0	>= preset	Preload
OV-Overflow
	Toggle True	1	1	0	dec by 1	Counting
UN-Underflow
	True	1	0	0	< preset	Done
	True	1	0	1	< -32768	Underflow

See page F-8 for a description of prescan operation for this instruction.

Compare Instructions

Instruction Description

LIM

LIMIT TEST (CIRC)

Low limit N7:10 3

Test	N7:15
	4
High limit	N7:20
	22

Limit Test

LIM

If the Test value (N7:15) is >= the Low Limit (N7:10) and <= the High Limit (N7:20), this instruction is true.

Low Limit	Test	High Limit	LIM
0	0	10	T
-5	5	10	T
5	11	10	F
10	0	0	T
10	5	-5	F
10	11	5	T

MEQ
MASKED EQUAL
Source	D9:5
	0000
Mask	D9:6
	0000
Compare	D9:10
	0000

Mask Compare Equal

MEQ

The controller takes the value in the Source (D9:5) and passes that value through the Mask (D9:6). Then the controller compare the result to the Compare value (D9:10). If the result and this comparison values are equal, the instruction is true.

Source	Mask	Compare	MEQ
0008	0008	0009	T
0008	0001	0001	F
0087	000F	0007	T
0087	00F0	0007	F

Publication 1785-UM012D-EN-P - July 2005