I need help with CX-Programmer Pneumatic Sequecing

[baub 0]

Hello!

Can you help me with a script that control 4 pneumatic cylinders? The script is something like that: When you press a buton, a first pneumatic cylinder is activated and after functioning 3 seconds, the first pneumatic cylinder stops. When the first cylinder stops, the second is started for 1 second and then it's stopped. After 3 seconds form the stoppage of the second cylinder, a third cylinder starts and function for 1 sec then it's stopped. Immediately after the stoppage of the third cylinder, a fourth cylinder starts and it's functioning for 5 seconds, then it's stopped and when the last cylinder it's stopped, the script resets.

I need a few rows, doesnt need to be 100% accurate, but to look like something there, cx it's not my element but i partially need it for my thesis. 

Maybe you can do this for practice i dont know, thank you!!

Edited 7 Jun 2020 by baub

[Rodney 21]

You have written the sequence of how you want the process to function. Now you should just put that sequence into your program. Have a go and we can give you helpful advice.

Rodney

[baub 0]

Hello! 

I have done something simplified in the way that each cylinders start after the previous cylinder it's stopped.

The problem it's that i dont know how to connect each start to process form the previous stop.

How does it look like? 

 

Edited 7 Jun 2020 by baub

[BITS N BYTES 66]

Suggest you review the STEP/SNXT instructions for your program.

What model PLC are you using?

[baub 0]

It doesn't matter, it's just theoretically.

[panic mode 246]

since it is purely time driven, this would do:

[Abdul Wajid 4]

@panic mode Is it necessary to use cylinder retract ? Wouldn't the cylinders will come back automatically to initial positions after comparing with timers in which the cylinders will get off directly? Why you mention advance along with cylinders ?

Edited 8 Jun 2020 by Abdul Wajid

[Rodney 21]

That would depend on the valves operating the system. If the valves are single acting then when the valve would return when de-energised. However double acting would require a return signal. This would depend on which operation is required.

Rodney

[baub 0]

Thank you so much sir!!

I tried to put this into a script. It's not 100% accurate but it's working like a chain in the way that each cylinder start after the previous is stopped, and that's enough for me.

 

Thank you guys!

Best regards!

 

Edited 8 Jun 2020 by baub

[Rodney 21]

Regarding your sequence Q100.0 will you be using this as an indication that the sequence is running ie a run lamp. If not you can use a internal flag so as to not waste a actual output. Also you require a cancel flag for T1,T2,T3 and T4. The way it is programmed T1,T2,T3 and T4 once they energise they cannot turn off.

Rodney

 

Edited 8 Jun 2020 by Rodney

[BobLfoot 301]

@baub Rodney makes an excellent point that T1, T2, T3 & T4 won't reset. 

I'd also ask what happens in your code if the operator forgets to open the main air supply valve?

Or what happens if one of the cylinders blows a seal and doesn't fully extend?

[Rodney 21]

Baub

 l have just noticed you have not used the inputs in the sequence as you did in your previous sequence.

Rodney

 

[panic mode 246]

9 hours ago, Abdul Wajid said:

@panic mode Is it necessary to use cylinder retract ? 

up to you... as others have pointed out, you may ignore last line 

[Abdul Wajid 4]

Thanks for the answer Rodney & Panic mode, have to go through it

1 hour ago, Rodney said:

l have just noticed you have not used the inputs in the sequence as you did in your previous sequence.

Good observation.... Seems like last one is according to the mentioned sequence in first post but timer reset is missing as you noticed.

[baub 0]

Thank you for your advices, i hope this time is better. I used inputs for each cylinder and  each cylinder start after the previous is stopped . The timer doesn't reset, but i have noticed that after the time is done (0001 for example), the output allocated to the respective timer turn off (100.01). Maybe it's better to use a reset point on the last line to rest all timers?