Omron PLC Two-Hand Safety Press Machine Programming

This article will discuss a Two-Hand Safety Press Machine System using Omron PLC CX-Programmer software. This system is designed to operate a press machine using a two-hand control system. The objective is to ensure that the operator must use both hands simultaneously to activate the press machine, thus minimizing the risk of injuries from workplace accidents.

Contents

Program Objective

PLC Based Two-Hand Press Machine Safety Logic

Initialization:

The PLC starts in standby mode.
The press machine can only be activated if both safety buttons are Pressed simultaneously.

Two-Hand Safety Logic:

Both safety buttons (Right and Left) must be Pressed at the same time.
If only one button is Pressed, the machine will not activate.
The press machine remains active for 5 seconds after both buttons are Pressed, then it will return to its initial state (inactive).

Operation Termination:

The press machine will Stop immediately if either button is Released.
The system will count the number of press processes completed.
The system returns to standby mode, waiting for both buttons to be Pressed again.

Two-Hand Safety Press Machine

IO Addressing

S.No.	Comment	Input (I)	Output(Q)	Memory Bit	Memory Word	Timers
1	PB_START	0.00
2	PB_STOP	0.01
3	PB_RIGHT_HAND	0.02
4	PB_LEFT_HAND	0.03
5	RESET_BUTTON	0.04
6	PRESS		100.00
7	SYSTEM_ON			W0.00
8	PRESS_COMMAND			W0.01
9	TEMP_BIT1				D0
10	COUNTER				D1
11	TEMP_BIT2				D2
12	TIMER_INTERLOCK					T0000

Omron PLC Programming

RUNG 0 (SYSTEM ON)

In this Rung, the memory bit SYSTEM_ON (W0.00) will be in the HIGH state when the PB_START (0.00) button is Pressed. Because it uses the KEEP(011) instruction, the memory bit SYSTEM_ON (W0.00) will remain in the HIGH state even though the PB_START (0.00) button has been Released.

The memory bit SYSTEM_ON (W0.00) will be in the LOW state if the PB_STOP (0.01) button is Pressed.

RUNG 1 (RIGHT HAND)

In this Rung, when the NO contact of the memory bit SYSTEM_ON (W0.00) in the HIGH state and the PB_RIGHT_HAND (0.02) button is Pressed, the value in the memory word TEMP_BIT1 (D0) will increase (+1).

When the PB_RIGHT_HAND (0.02) button is Released, the value in memory word TEMP_BIT1 (D0) will decrease (-1).

RUNG 2 (LEFT HAND)

In this Rung, when the NO contact of the memory bit SYSTEM_ON(W0.00) in the HIGH state and the PB_LEFT_HAND (0.03) button is Pressed, the value in the memory word TEMP_BIT2 (D2) will increase (+1).

When the PB_LEFT_HAND (0.03) button is Released, the value in the memory word TEMP_BIT2 (D2) will decrease (-1).

RUNG 3 (TIMER)

When the NO contact of the memory bit SYSTEM_ON (W0.00) becomes in the HIGH state and the value in the memory word TEMP_BIT1 (D0), TEMP_BIT2 (D2) is Equal To “1”, then the TIMER_INTERLOCK (T0000) Timer will count up to 5 seconds.

RUNG 4 (OUTPUT PRESS)

When the NO contact of the memory bit SYSTEM_ON (W0.00) becomes in the HIGH state and the value in the memory word TEMP_BIT1 (D0), TEMP_BIT2 (D2) is Equal To “1”, then the output PRESS (100.00) will be ON.

If the NC contact of the TIMER_INTERLOCK (T0000) Timer is in the HIGH state, then the PRESS (100.00) output will be OFF.

RUNG 5 (COUNTER)

When the NO contact from the PRESS (100.00) output is ON, the value in the memory word COUNTER (D1) will increase (+1).

RUNG 6 (RESET COUNTER)

When the RESET_BUTTON (0.04) button is Pressed, the value in the memory word COUNTER (D1) will be reset to zero “0”. Because the Move instruction moves the zero “0” value to the memory word COUNTER (D1).

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