13
2TLC172001M0211_A
4.2
IQ.. Digital failsafe inputs / Digital outputs (non failsafe)
This type of IO-terminals provides 4 different functions. Each terminal is connected to both
processors and may therefore be used as a failsafe input.
Each terminal is also equipped with an output transistor giving the user the possibility to
configure it as either a failsafe input or non failsafe output. The outputs are intended for
functions that do not require redundancy. E.g. indicators and status signals.
4.2.1 Dynamic signals
The IQ-terminals can be configured as dynamic outputs A, B or C for supplying inputs. When
an output is configured as dynamic, a unique pulse train is generated. A safety input can then
be configured just to accept this specific pulse train as input condition and the system will
detect external short circuit conditions. (See separate description).
4.2.2 Current monitoring IQ16, IQ17 (Only A20)
See 6.9
Failsafe inputs, Outputs (non failsafe), Dynamic outputs
IQ
1
0
B
A
CPU
Current monitored (only A20)
IQ
1
5
IQ
1
6
IQ
1
7
A
B
A
B
A
B
