Danfoss VACON OPTEA User Manual

The monitored ramps are defined with two shared ramp definitions that the other safety functions than the SQS function can use to
calculate the actual ramps. The SQS function has its own ramp values. The ramp definition has a maximum and a minimum time
that is permitted for the ramping.
N O T I C E
When a safety function uses a ramp, the related ramp must be defined. It is not necessary to parameterize both minimum and
maximum ramps if they are not necessary for the application.
Deceleration ramps are defined by a nominal speed value and two time values that represent the maximum and minimum time
that the ramping from the nominal speed is permitted to take. The actual monitored ramps are calculated when ramp monitoring
starts. The ramps are defined as slopes between the request moment and the parameterized times (SS1 used as an example).
SS1_Dec_Max s = 
Speed rpm × Rampx_Dec_Time_max s
Rampx_speed rpm
SS1_Dec_Min s = 
Speed rpm × (Rampx_Dec_Time_min s − SS1_td1 s )
Rampx_speed rpm
where Speed[rpm] is the speed at the time of the calculation. SS1_Dec_Max and SS1_Dec_Min are the time from ramp start (points
A and B) to where speed should be zero (points C and D). Rampx_speed is the nominal speed for the used ramp set. See the figure
below. At any given point during the ramp monitoring, the actual value of monitoring is calculated from the slope connecting the
respective points. The area outside the permitted speed range during ramp monitoring is shaded.
N O T I C E
Use of ramp monitoring is not recommended when only proximity sensors are used as speed sensor.
A
C D
B
Rampx Speed
Rampx Dec Time Max
Nominal deceleration ramp
Rampx Dec Time Min
SS1 Dec Max
SS1 Dec Min
SS1 td1
Speed
Zero Speed
t
Speed
Scaled deceleration ramp
e30bi366.10
Illustration 26: Deceleration Ramp, the SS1 Function as an Example
A
Start of the minimum deceleration ramp
B
Start of the maximum deceleration ramp
C
End of the minimum deceleration ramp
D
End of the maximum deceleration ramp
Ramp monitoring does not continue in the safe speed range of the safe monitoring function. For example, for the SLS function, the
maximum ramp value is limited to the selected SLS limit. This can be noted, for example, with long SLS td2 delays. The minimum
ramp monitoring stops when the monitoring value would be below the selected SLS limit.
AQ319736045637en-000101 / DPD01798 | 65Danfoss A/S © 2021.06
Safety Functions
VACON® NXP Advanced Safety Options
Operating Guide

Danfoss VACON OPTEA Specifications

General

Brand	Danfoss
Model	VACON OPTEA
Category	DC Drives
Language	English