Cscape ramp/soak function

[Syriss]

Alright, so the other day I finally figured out a way to create a ramp function in cscape to allow me to steadily move my analog output from 0V to 5V on my horner he-xe105.

2 Questions:

Did I go about achieving this function in an efficient way? If not, how could I improve it?

I am having a real hard time figuring out how to have it hold the final value steady for a set time period, and then ramp down slowly back to 0V. Could anyone help me accomplish this task?

Attached is a screen capture of the cscape ladder that I currently am trying to work with.

Thanks in advance for your help!

 

[Lancie1]

First, you will need a Latch relay (call it R1) to lock out the ADD function when AQ010 = 15950. This Latch relay R1 stays set until Reset at the end of the Down Ramp. You may can put this Latch relay R1 on a rung branch parallel with the R0003.1 output, or it could need a separate rung depending on the capabilities of Cscape. When R1 is ON, it locks out the ADD function so that it cannot add to AQ010.

Second, you need another parallel branch to the ADD instruction that does a SUBtract when R1 = ON. This SUB function should cause the reverse action of the ADD function (after the UP Ramp is done, and R1 = ON).

Third, at the end of the Down Ramp (AQ010 = 175), you need to reset R1 ONE TIME ONLY, so that the cycle can repeat, if desired.

 

[Syriss]

Thank you for the quick reply. I'm not familiar with a latch relay. How do I set one up?

 

[Lancie1]

You need a way to lock in a relay or device that says basically "UP Ramp has been finished". Without that, it will be difficult to get your logic to do the Down Ramp.

Most programming languages have a type of relay that, once turned on or SET (sometimes called LATCH), it stays on without any further inputs of any kind. It only goes off when a special RESET or UNLATCH is triggered.

If Cscape does not have a SET or LATCH or something similar, then you can create your own using an ordinary relay like this:

 

|                   Unlatch           |

|   AQ010 = 15950     R2      Latch   |

|---+----| |----+----|/|------(R1)----|

|   |           |                     |

|   |    R1     |                     |

|   +----| |----+                     |

|                                     |

|   AQ010 = 175              Unlatch  |

|--------| |------------------(R2)----|

|                                     |

 

[Syriss]

Ah ok. Cscape has a "set" coil, I just never knew what it was for exactly. Thanks

 

[Lancie1]

Great news. For triggering the SET coil, you may need to use a "Greater Than or Equal" comparison instead of an EQUAL. If the value of AQ010 can get set greater than 15950, then using an EQUAL comparison could cause an error. The same logic applies for the RESET function: you may need a "Less Than or Equal" to avoid problems.