Function blocks
92 Function blocks for TwinSAFE logic components
3.9 The function block EDM
3.9.1 Functional description
The FB EDM (External Device Monitor) is used for time monitoring of signals Mon1 and Mon2. Switch-on
and switch-off monitoring can be configured. In default state both monitoring functions are inactive. At
least one of the two monitoring functions must be enabled.
Switch-on monitoring checks whether signal Mon2 is set to 0 within the set time (maximum 10000 ms)
following a switch from 0 to 1 of signal Mon1.
Switch-off monitoring checks whether signal Mon2 is set to 1 within the set time (maximum 10000 ms)
following a switch from 1 to 0 of signal Mon1.
If the set monitoring time is exceeded, the FB EDM enters the error state (FbError) and sets the Error
output to 1. The error state can only be exited through acknowledgement via the ERR ACK input of the
associated TwinSAFE group.
Figure 3-42: EDM function blocks
To Next Page
Loading...
Need help?
General
