Beckhoff TwinSAFE logic FB User Manual

System description
12 Function blocks for TwinSAFE logic components
2.1.1 TwinSAFE group
The function blocks are assigned to a TwinSAFE group. All outputs of the group adopt a safe state in the
following situations:
− communication error in an assigned TwinSAFE connection,
− error in an assigned function block (e.g. a discrepancy timeout)
− error in the assigned local outputs.
The safe state is always the non-energized state at the output, which corresponds to logical 0. The data
of a TwinSAFE connection (and therefore of a TwinSAFE input or TwinSAFE output terminal) are always
assigned to exactly one TwinSAFE group.
A communication error is indicated by the output (COM ERR) of the TwinSAFE group and acknowledged
via the ERR ACK input. A function block error is displayed on the output FB ERR and acknowledged on
the same input ERR ACK as the communication error. An error on the local outputs (only KL6904) is
displayed on the third output OUT ERR and once again acknowledged by the same input ERR ACK. The
secure state of the TwinSAFE group outputs is removed once the error is no longer present and has been
acknowledged.
Apart from this the TwinSAFE group has an input (RUN), with which the processing of the assigned
function blocks can be stopped and started. All TwinSAFE group assigned outputs are in a safe state
when stopped. For the EL6910 and newer logics the RUN input must always be linked with a standard
signal.
NOTE
Run and ErrACK in the TwinSAFE group
The error acknowledgement is not automatic, i.e. the input ERR ACK must always be linked with a
standard signal.
For the EL6910 and newer logics, the RUN input must also always be linked with a standard signal.
2.1.1.1 Inputs and outputs of the TwinSAFE group EL6900/KL6904
Table 2-1: Inputs of the TwinSAFE group
Name
Permitted type
Description
RUN
FB-Out
Standard-In
TRUE:
The function blocks assigned to the TwinSAFE group are executed
FALSE:
All of the TwinSAFE group assigned function blocks are at a STOP
state and thus all associated outputs are in a safe state
When the input is not linked it is in the TRUE state
ERR ACK
FB-Out
Standard-In
The signal sequence FALSE->TRUE->FALSE acknowledges all
errors in the assigned function blocks and the TwinSAFE
connections.

Beckhoff TwinSAFE logic FB Specifications

General

Brand	Beckhoff
Model	TwinSAFE logic FB
Category	Industrial Electrical
Language	English