Beckhoff TwinSAFE logic FB User Manual

Function blocks
Function blocks for TwinSAFE logic components 127
3.17 The function block SUB
3.17.1 Functional description
The FB SUB is used to subtract the AnalogIn2 input from the AnalogIn1 input and transfer it to the
AnalogOut output. The input data types INT16, INT32, UINT16 and UINT32 are permitted. The output
must be selected to match the input types.
If an overflow or underflow occurs during the subtraction, the ERROR state is assumed. The AnalogOut
output is then set to 0, the Error output is set to 1.
Once overflow or underflow no longer occurs after an error, the function block can be set to RUN state
again via ErrAck of the TwinSAFE group. The RESET state is assumed when the ErrAck input of the
corresponding group is 1. When the ErrAck input of the corresponding group changes to 0 again, the
system switches from RESET state to RUN state. In RESET state the AnalogOut output and the Error
output are 0.
Figure 3-72: Function block SUB
NOTE
KL6904/EL6900
The function block SUB is not available in the KL6904 and the EL6900.
3.17.2 Signal description
Table 3-99: FB SUB inputs
Name
Permitted type
Data type
Description
AnalogIn1
TwinSAFE-In
FB-Out
Standard-In
TwinSAFE SC
INT16
INT32
UINT16
UINT32
1st input channel for subtraction
AnalogIn2
TwinSAFE-In
FB-Out
Standard-In
TwinSAFE SC
INT16
INT32
UINT16
UINT32
2nd input channel for subtraction

Beckhoff TwinSAFE logic FB Specifications

General

Brand	Beckhoff
Model	TwinSAFE logic FB
Category	Industrial Electrical
Language	English