Festo CAMC-G-S3 Manual page 99

2 Product description of safety module CAMC-G-S3
When the safety function SSF0 is requested (VOUT_USF0_SFR), a calculation for a speed ramp is carried out,
so that the drive will perform within the approved speed corridor, starting at the current speed:
– Calculation of the initial values n
value. A start window around the current speed is first calculated based on a gain parameter "Slow­
down ramp - Starting value factor" (P0E.04/...) and an offset parameter "Slowdown value - starting
value offset" (P0E.05/...).
– The position of the start window is set relative to the desired speed corridor and the initial values
are adapted as necessary to produce a trapezoidal, tapering speed corridor (è Fig. 2.25).
– The start time of the ramp can be specified using "Slowdown ramp - Time delay to start"
(P0E.06/..., minimum value: 6 ms) and the end time of the ramp via "Time for slowdown ramp"
(P0E.02). After P0E.02 has elapsed, the stationary speed corridor has been reached and SSF0
issues the signal VOUT_USF0_SSR (when the actual speed is in the approved range!).
– Using "Time delay until monitoring starts" (P0E.01/...), it is possible to specify from when the SSF0
function monitors the speed.
A delay of the ramp via "Slowdown ramp - Time delay to start" (P0E.06/...) is always
preferable when the axle is braked by the functional controller and is transferred to the
monitored speed corridor. P0E.06 can be used to compensate the reaction time of the
functional controller.
The safety module can actively manipulate the controller of the basic unit, thus actively limiting the
speed of the axle. The limit values are transferred at regular intervals to the basic unit:
– This function is activated by setting the parameter "Actively limit speed in basic unit" (P0E.09/...).
– There are additional parameters to ensure that the monitored limit values are complied with safely
during active limiting of the speed in the basic unit:
– Using the minimum value of "Slowdown ramp - Time delay to start" (P0E.06, 6 ms) compensates
for the time it takes to transfer the new limit values to the basic unit, before the control is manip­
ulated in the basic unit.
– "Rotational speed ramp - monitoring time delay" (P0E.0D/...) can be used in order to add a
speed limit delay in the safety module of several additional milliseconds, to monitor for a tar­
geted delay of the speed limit in the safety module for monitoring. This gives the basic unit addi­
tional time, for example, if a jolt-limited travel profile was selected in the basic unit and braking
may only take place with jolt limiting.
– Finally, a speed offset can be parameterised using "Speed limit offset" (P0E.0C/...). The speed
limits for the basic unit are then around P0E.0C/..., offset within the speed corridor for monitor­
ing, meaning that slight deviations of the actual speed do not lead to a response from the monit­
oring system.
– If the upper and lower speed limits for the basic unit overlap, due to a very narrow corridor and
the offset P0E.0C/..., then both limits are set to the average value between the monitored min­
imum and maximum rotational speed.
Festo – GDCP-CAMC-G-S3-EN – 1406NH – English
and n is based on the current speed n
max min
as the starting
act
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