Reer MZERO Installation, Use And Maintenance Manual page 80

Example of operation in the "Mandatory Gate Opening" mode
In this example the user unlocks the guard lock with the "SWITCH" block. The "LockOut" signal
controls a "STATUS" SIL 1/PL c output that controls the guard lock electromagnet, the status of
which is detected by the "LOCK FEEDBACK" input block. "Output1" indicates the status of the
operations.
The status of the safety gate is monitored by the "Gate" input via the "E_GATE" input block, the
"Mandatory Gate opening" parameter is selected.
The guard lock used in the example continues to be locked when the electromagnet is not
energised. Hence the "Interlock spring" option must be selected.
Figure 37 Example of operation in the Mandatory Gate Opening mode
➔
The Guard Lock operator parameters are shown on the right. On the left there is an example
of an application diagram. The electromagnet feedback consists of two contacts, one
normally closed and one normally open. When the electromagnet is energised the two
contacts switch status. The gate feedback consists of two normally closed contacts.
Figure 38
shows the traces relative to the operation. These are described in detail below:
(1) At this time the user requests to unlock the guard lock. The "COMMAND" signal switches
from LL0 to LL1, and the "Output1" signal switches from LL1 to LL0.
(2) At this time the electromagnet is activated with a delay of "Unlock Time", after the
command is sent. This delay has been set to 0.5 seconds. The "ACTIV." signal switches from
LL0 to LL1.
(3) At this time the electromagnet is actually activated, 95ms after the command was sent.
This delay is due to the technical characteristics of the electromagnet. In any case, 95ms is
less than 100ms ("Feedback Time") and so no errors have occurred.
(4) At this time the guard lock is unlocked and the user opens the gate. The FBK_GATE signal
switches from LL1 to LL0.
(5) At this time the user closes the gate and the FBK_GATE signal thus switches from LL0 to
LL1.
(6) At this time the user releases the unlock gate command. The "Guard Lock" detects the gate
closed condition, via the FBK_GATE signal, and sends a command to lock the guard lock.
The "ACTIV." signal switches from LL1 to LL0.
(7) At this time the electromagnet is actually deactivated, approx. 95ms after the command
was sent due to the technical characteristics of the device. The guard lock is now locked.
(8) As soon as the "Guard Lock" operator detects that the guard lock is locked and the gate is
closed, the "Output1" signal switches to LL1.
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STAND ALONE PROGRAMMABLE SAFETY CONTROLLER
8541403 • 19/07/2021 • Rev.1