Two Hand Control

Good morning all.

Is it possible to program two inputs that have to happen at the same time. 

For example; to operate a cutting cycle on a machine so that the operator has to have both hands on the controls and not near the machine. I have tried using various combinations of inputs, function blocks and timers but it still appears easy to defeat, so I must be missing something.

Perhaps I'm missing something, however to me it sounds like an AND block? 

Connect 2 inputs and the output will only become active once both are active. 

Hello.

Zazu

Good morning all.

Is it possible to program two inputs that have to happen at the same time. 

For example; to operate a cutting cycle on a machine so that the operator has to have both hands on the controls and not near the machine. I have tried using various combinations of inputs, function blocks and timers but it still appears easy to defeat, so I must be missing something.

One option:

Notice that actual regulation two hand control is more complex and needs certification.

The reason for the above design:

• The two buttons should be activated within a time period from each other. This prevents the user of bypassing the one switch in some clever way. (example: box sealing tape)
  
  
• It is not humanly possible to activate the buttons at the very same millisecond. The timer used here is short but not impossible short.

Zazu

For example; to operate a cutting cycle on a machine

 Dear Zazu,

please Safety First!!      LOGO! no have safety outputs!! 

PNOZsigma safety relay for two-hand monitoring - Pilz GB

Having looked up current legislation I think this will have to be the way.

Many thanks to all who responded.

Intresting topic,Currently with our safety being of an importance it is possible I currently replaced a specially built relay for situations for this 2 hand control having movement but both hands on push buttons,Which will be only using 1 Input on relay but wiring done hardware on relay.