
Formula symbols
Description
T
deceleration
Machine stopping time
T
others
Other application-specific variables, such as the response time of
the contactors
4.5
Integrating the equipment into the electrical control
NOTE
Several safety functions are generally necessary in order to ensure a safe design for the
entire application. This requires additional components that are not part of the safety
system, such as switches, fuses, and contactors. The circuit diagrams contain informa‐
tion on wiring the safety system with additional components within an application.
4.5.1
Circuit diagram
A more detailed circuit diagram for Safe Entry Exit is available online:
The components of Safe Entry Exit are interconnected per the following diagram:
ESPE Type 4
Independent Control System
Process
sensor
Control unit
(e. g. PLC)
Signal MR
Muting request
Signal TE
Time extension
OSSD
Safety System
Safety Controller Flexi Soft
Safety Outputs
In
pu
ts
Out
put
s
CPU
Logic
Figure 2: Block diagram for Safe Entry Exit
Table 2: Block diagram terminology
ESPE Type 4
The electro-sensitive protective device must conform to Type 4 and
can be a safety light curtain, for example.
Independent Control Sys‐
tem
The signals of the higher-level control are part of the initiation of
the muting function. The combination of process sensor and con‐
trol unit is an example. The higher-level control is not part of the
safety system.
Process Sensor
The process sensor forwards information about transported mate‐
rials to the control unit. It must not be easy to manipulate this
information, e.g., by modifying it.
Control unit
The control unit is a functional unit of the process that controls the
command processing sequence. It can be a standard programma‐
ble logic controller, for example.
OSSD
Safety output of the Type 4 electro-sensitive protective device con‐
nected in pairs and subject to dual-channel evaluation.
Signal MR - Muting request This signal requests the muting function.
Signal TE - Time extension
This signal is used to request the time extension function.
Safety Controller
The safety controller monitors the signal change and switches
accordingly.
Inputs
Safety controller inputs
4
PROJECT PLANNING
20
O P E R A T I N G I N S T R U C T I O N S | Safe Entry Exit
8021675/ZV26/2019-05-13 | SICK
Subject to change without notice