Anti tie down palm buttons

[Tim]

Why would you want to use one timer? When it comes to safety, wouldn't you want to use two for double redundancy?

Why? Because you could put as many timers you want to in the PLC logic and still never call it redundant. If the safety requirements are for the use of an ANTI-TIE down circuit, then we wouldn't be talking about plc code.

 

[cnrservices]

I am wondering if Paul Rupert and Jessica are in the same class?

I think one of them should tell their teacher that they are NOT going to try & program anything so silly and unrealistic.

If one of these students do end up as a programming engineer their experience in this class will set dangerous precedents for them to follow - "My Professor said to program a stamping press with 2-hand controls using a common PLC and only 1 timer" wont hold up under any OSHA investigation of the impending double amputation inquiry.

 

[Rick Densing]

It is a fine excercise. Like Ron said, it is not always about safety. Second, two hand control is only marginally safer than a single button. If you are relying on that alone for safety, you will have trouble on you hands.

 

[rsdoran]

Original question:

Is there away to program palm buttons using
only one timer in the anti tie down ??

Answer: Yes, several versions have been shown.

I want to know where it was stated this was a "press" of any kind? We all understand what assume means?

I stated before and will state again..."The use of palm buttons or 2 hand control does not always imply a safety issue."

 

[PAUL RUPERT]

I have attached a file for everyone to read.

 

[Mtn_Bkng_Dave]

Original question:

Answer: Yes, several versions have been shown.

I want to know where it was stated this was a "press" of any kind? We all understand what assume means?

I stated before and will state again..."The use of palm buttons or 2 hand control does not always imply a safety issue."

Thanks..........I was beginning to think I was the only one that noticed this.

And Elevmike the only problem with your original code is that the run coil will strobe everytime the timer times out.......

Dave

 

[elevmike]

Dave,

If you will notice, my post here is a screen shot from DirectSoft. In and effort to avoid severe embarassment, I tested the code before I posted it. The N/C contact just before the timer prevents the timer from comming on to drop the RUN coil.

I understand what your looking at though.. And thats why Tim's code here is a cleaner version. Dispite my best efforts Tim embarassed me a little, but I'll get over it in a few weeks.

Mike