GE GFK-0804B manual Set/Reset Coil Pair, Example and HHP Instructions Set

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Set/Reset Coil Pair

The Set/Reset coil pair can be used to control the state of an associated reference. The Set coil sets the reference to 1. The reference (O17 in the example below) STAYS set to 1 until it is reset to 0 by the Reset coil. Notice that the Set and Reset coil are programmed with the same associated reference; that of reference being controlled.

In the example below, the Set coil and Reset coil are shown in adjoining rungs of logic. That is not necessary, however.

Programming Software Instructions

If you are using the programming software, refer to the instructions on page 4-11.

Example and HHP Instructions

Set	SET
	Ladder Diagram
I1	O17
	SET
I2	O17
	RST

Timing Diagram

Input I1

Input I2

Output O17

Reset		RST	46023
	Hand-held Programmer
START			I1
OUT	F2 (SET)		O17
START			I2
OUT	F2(RESET)		O17

This is a flip-flop operation. Input I1 sets output O17 to 1. Output O17 remains 1 even if I1 changes to 0. Output O17 is only reset to 0 when I2 is activated.

When both I1 and I2 are ON, the last occurrence in the scan (RST in this case) takes precedence.

GFK-0804B Chapter 4 The Micro PLC Instruction Set 4-13