Application example: Safety Functions
A.3 Safety program S7 Distributed Safety
Fail-safe operation of the Mobile Panel 277F IWLAN
Function Manual, 08/2008, 6AV6691-1FQ01-2AB0
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A.3
Safety program S7 Distributed Safety
Functionality
The safety program of the S7-CPU takes care of the following:
● The "override" mode is started when the Mobile Panel 277F IWLAN is logged on at the
effective range and there is a positive edge on the override switch.
● When the Mobile Panel 277F IWLAN is logged on at the effective range in which the
override switch is located, the signal lamp comes on.
● The "override" mode is terminated if either the override switch is activated again or if the
operator leaves the protected area and steps on the contact mat.
● If the "override" mode is active, the operator can control the robot by pressing a function
key on the device and at the same time confirming operation with the enabling button.
● After an emergency stop, the plant only restarts when the operator has performed an
additional acknowledgment.
● In the event of a rampdown or shutdown, the appropriate plant-specific responses are
initiated.
Program execution of the safety program
Structure
The safety program is structured as follows:
)%
)B)%B03))%
)B)%B51*))%
)B(6723))%
)&DOO
)&
Symbolic names used
The following symbolic names are used in the networks of the sample programs
Symbolic name
Meaning
F00256_Mobile277Failsafe_IO
Fail-safe I/O DB of HMI device
MP1_FB_S7_MP_RE
Input which is set when a reset of the HMI device is performed
from the F-CPU.
MP1_FB_S7_ACK_ERR
Input which is set when a communication error is acknowledged
from the F-CPU.
MP1_F_DATA_PII
Word 1 of the PII of the HMI device
MP1_F_RANGE_PII
Word 2 of the PII of the HMI device
