Safe Limited Speed - OEM Automatic AB

Chapter 1
Safety Concept
Safety Reaction Time
The safety reaction time is the amount of time from a safety-related
event as input to the system until the system is in the Safe State.
The safety reaction time from an input signal condition that triggers a
safe stop, to the initiation of the configured Safe Stop Type, is 20 ms
(maximum).
The safety reaction time from an overspeed event that triggers a safe
stop, to the actual initiation of the configured Safe Stop Type, is equal
to the value of the P24 [OverSpd Response] parameter.
For more information on overspeed response time, see Overspeed
Response Time on page 75.
Considerations for Safety
Ratings
The achievable safety rating of an application using the MSR57 relay is
dependent upon many factors, including the encoder setup, drive
options, output pulse testing, and the type of motor.
When using two independent encoders to monitor motion and when
installed in a manner to avoid any common cause dangerous failure,
the MSR57P relay can be used in applications up to and including
SIL CL3, PL(e), and CAT 4.
When using a drive with the Safe-Off option and one external
contactor, or when using two external contactors, the MSR57P relay
can be used in applications up to and including SIL CL3, PL(e), and
CAT 4.
IMPORTANT
Some of the diagnostics performed on the encoder signals
require motion to detect faults. You must make sure that motion
occurs at least once every six months.
18 Publication 440R-UM004A-EN-P - December 2008