28 February 2021
Understanding PID wake up function
Altivar 61 and 71
All models and serial numbers
There is no specific rules for define when use one and when use other. It is dependent on the application but especially on the need and on the custom of the customer. Some people are going to think in % of error with regard to the PID reference while of the other one is going to think in value with regard to the PID feedback. These 2 parameters have the same purpose but the method is simply different.
The following list the three ways to configure PID Sleeping/Wake up in menu 1.7 Application Function
1. [SLE] Sleep Offset Threshold (ATV61 only)
2. [rSL] PID wake up Threshold (ATV71 only)
3. [UPP] PID Wake up Threshold (ATV61 and ATV71)
(1) Sleep Offset Threshold [SLE] – Frequency above low speed at which the
drive wakes up.
Set Low speed timeout [tSL]
Set Low speed [LSP]
Set Sleep Offset Threshold [SLE]
Following operation at LSP +SLE for a defined period
Low speed [LSP] = 20
Low speed timeout [tSL] = 60
Sleep Offset Threshold [SLE] = 10
The drive will sleep when the drive runs at low speed for 60 seconds
The drive will wake up when the speed reference is 30 hz.
(2) [rSL] Restart error Threshold – The difference between the set point [rPI]
and the feedback [rPF].
To wake up the drive, the PID error [rPE] must equal the Restart error
If Set point [rPI] = 500 and Error [rSL] = 30
The drive will wake up when the PID error [rPE] is 30 below the Set point
(3) [UPP] Restart feedback Threshold – The actual set point at which the drive
will wake up.
To wake up the drive the PID Feedback will be equal to the PID Wake up
If Set point [rPI] = 500 and Wake up thres. [UPP] = 470
The drive will wake up when the PID Feedback [rPF] = 470.