ICS-TOUCH Instruction Manual
CEB00XXX-53-000
Page 27 of 43
Issue 4 19 January 2021
8
Mismatch Detector
The ICS-6-SP trips out and disables the laser when either of its two safety circuits opens. If all the
door interlock and emergency stop switches have two contacts, one in each safety loop, then it is
normal for both safety circuits to open more or less simultaneously.
When the ICS-6-SP Safety Circuit Mismatch Detection is enabled, if the second safety circuit does not
open within a short time of the first (typically around 1 second), a mismatch is triggered and the
Mismatch Fault symbol is shown on the touch panel. It is then not possible to arm the system.
Safety Circuit Mismatch Detection can only be used if all inputs to the ICS-6-SP Control Unit are dual
channel. This includes all the door contacts and emergency stop buttons. If any input only operates
one channel, then a mismatch will inevitably occur, and the mismatch detector will be triggered. In
the event that it is not possible for all of the inputs to be dual channel, the mismatch detector must
be disabled as described later in this section. Note that the use of a single channel safety contact and
the disabling of the mismatch detector will reduce the achievable safety performance level of the
system.
8.1 Configurable Options for Safety Circuit Mismatch Events
Mismatch Event Behaviour
In the event of a mismatch being detected either of the following two actions are available
depending on the option switch settings:
a) Lock out, preventing further use, unless the system is reset by switching it off and on again;
b) Lock out, preventing further use, unless the system is attended to by a qualified technician.
Option a) is suitable for mission-critical applications where the inability to use the laser would be
costly or inconvenient. Having detected and indicated that there is a fault it allows the system to be
reset to operate on the one good safety circuit provided the faulty circuit has been closed. The need
to manually reset the system before it can be used provides a clear indication to operators that
there is a problem that needs to be addressed at the earliest opportunity and that other risk
limitation steps may be required in the interim. An example might be to secure the affected door out
of use until it can be repaired.
Option b) is the lowest risk option, as once a safety circuit fault has been detected the system cannot
be used. The ICS-6-SP can only be reset by opening the cabinet in which it is mounted and operating
the Fault Reset button. Procedures should indicate that this is only carried out by suitably trained
technicians once the fault has been repaired.
By default, the mismatch detector is factory set to be enabled in option ‘a’ above.
To change the settings of the Safety Circuit Mismatch Detection the configuration links must be
accessed by removing a cover as shown below.
