ICS-6-OEM Instruction Manual
01807-53-000
Page 24 of 32
Issue 5 19 January 2021
Pre-Check Mismatch Detection and Safety Logic Plus
Safety relays used on expansion cards are also monitored for mismatch, so should any of these
relays become stuck a mismatch is signalled. The Safety Logic Plus interface card generates a
mismatch event during its start-up sequence, so if this expansion card is being used the precheck
mismatch detection must be disabled. To do this remove the bottom terminal cover as shown below
and close the jumper. Refit the terminal cover afterwards. Mismatch detection of the safety circuits
is still provided in this mode.
8.2 Clearing a Mismatch Fault Indication
In all cases the fact that a Mismatch Fault has been indicated warns users that the safety of the
system may be compromised. Site-specific instructions should indicate the actions to be taken by
users in such an event.
Depending on the internal settings made above, the system may, or may not, be temporarily cleared
by turning the power supply off, waiting for ten seconds, then turning it back on again. In this case
the system should be attended to by a suitably qualified technician to identify and repair the fault at
the earliest opportunity as a fault has been identified and the system may cease to provide
protection without further warning.
If the ICS-6-OEM has been configured to permanently lock out, it can only be reset by pressing the
Mismatch Reset button using a suitable tool through the hole in the cover shown below. This should
only be undertaken by suitably qualified technicians once the fault has been identified and repaired
as otherwise the unit will just lock out again.
