GE GFK-0804B manual Compare Functions, Examples, Equal, Greater, Less

4

Compare Functions

The Compare functions are used to compare the contents of two registers. They can be used to activate an output, or as conditional logic to other program functions.

The Micro PLC Instruction Set includes these Compare functions:

Equal	Passes power flow to the right in the rung if the contents of
	the two registers are equal.
Greater	Passes power flow to the right in the rung if the number in the
	first register is greater than the number in the second.
Less	Passes power flow to the right in the rung if the number in the
	first register is less than the number in the second.

Greater or Passes power flow to the right in the rung if the number in the

Equal first register is greater than or equal to the number in the se- cond.

Less or Equal Passes power flow to the right in the rung if the number in the first register is less than or equal to the number in the second.

Not Equal Passes power flow to the right in the rung if the number in the first register is not the same as the number in the second.

An output in the same rung will be set to 1 when the condition being tested for is met.

Examples

Ladder Diagram

O17

[R1 = 5]

O18

[R1 > R2]

O19

[R3 < R4]

O20

[R4 > R6]

O21

[R7 < R8]

O22

[R9 0 R10]

46142

Equal	Output O17 is activated when
	contents of R1 = 5.
	Output O18 activated when con-
Greater	tent of R1 is greater than content
	of R2.
	Output O19 activated when con-
Less	tent of R3 is less than content of
	R4.
	Output O20 activated when con-
Greater or	tent of R4 is greater than or equal
Equal	to content of R6.
Less or	Output O21 activated when con-
Equal	tent of R7 is less than or equal to
	content of R8.
Not Equal	Output O22 activated when con-
	tent of R9 is not equal to content
	of R10.

4-36 Micro PLC Programmer's Guide ± April 1994 GFK-0804B