Interfaces for BML Magnetic Encoder System
2
Interfaces (continued)
Selecting safety functions
In the following some safety functions are listed according
to EN 61800-5-2 which can be used to use BML sensors
with the G-interface.
To implement the safety function the sensor must be used
in a safe overall application. Here the user must take into
consideration the entire safety chain of the safety function
(e.g. use of a safety controller with appropriate safety
program).
a) Safe operating stop
(Safe operating stop, SOS)
After reaching a stop at time t1 the drive is held in position
in a controlled manner.
v
SOS
Fig. 2-18:
Distance-time diagram for safe operating stop
b) Safe stop 1
(Safe stop 1, SS1)
With the trigger at time t1, e.g. E-Stop, the drive is rapidly
stopped. At time t2 the drive is made torque- and force-
free.
v
Trigger
STO
t1
Fig. 2-19:
Distance-time diagram for safe stop 1
c) Safe stop 2
(Safe stop 2, SS2)
With the trigger at time t1, e.g. E-Stop, the drive is rapidly
stopped. The drive is then brought to the position.
v
Trigger
SOS
t1
Fig. 2-20:
Distance-time diagram for safe stop 2
22
english
t1 t2
t
t2 t3
t
t2 t3
t
d) Safely-limited speed
(Safely-limited speed, SLS)
Monitors whether the drive is below a certain rpm or
speed. This is the case in Fig. 2-21 starting at t1.
v
Limit
SLS
Fig. 2-21:
Distance-time diagram for safely-limited speed
e) Safe speed monitor
(Safe speed monitor, SSM)
A signal is generated when the rpm/speed of the drive is
below a certain limit. In Fig. 2-22 this is true from t1 to t2
and from t3 to t4.
v
Limit
SSM
t1
Fig. 2-22:
Distance-time diagram for safe speed monitor
f) Safe direction
(Safe direction, SDI)
The movement direction for the drive is monitored.
v
SDI
t1
Fig. 2-23:
Distance-time diagram for safe direction
g) Safely-limited position
(Safely-limited position, SLP)
Monitors whether the drive leaves a defined travel range.
This is the case in Fig. 2-24 between t1 and t2.
s
Limit
SLP
t1
Fig. 2-24:
Distance-time diagram for safely-limited position
t1 t2
t
t2
t3
t4
t
t
t2
t