Rockwell Automation Guardmaster 440R-ENETR, Руководство пользователя, Страница: 69 / 86

Rockwell Automation Publication 440R-UM009C-EN-P - July 2019 69
Studio 5000 Example Logix Code Chapter 8
Guard Locking with Fault Reset Command
Figure 53 on page 70 shows an example of how the lock, unlock, and fault reset
commands can be used. In this example, a guard locking interlock switch (like the
TLS-ZR or 440G-LZ) is connected to tap 4. Momentary, normally open push
buttons initiate the lock and unlock commands. The logic initiates the fault reset
command automatically.
The safety outputs of the guard locking switch can be OFF for various reasons:
• The switch is unlocked.
• The gate is not closed.
• The switch has faulted.
If the gate is not closed and a lock command is issued to the tap, the tap and
switch do not fault. If the gate is then closed, the tap does not automatically lock
the gate. The operator must issue an unlock command, followed by a lock
command.
The GuardLink taps only know that the safety outputs of the switch are OFF.
The example logic allows an operator to attempt to lock the switch twice. If on
the third attempt, the switch does not lock, the logic automatically sends a fault
reset command to the tap. The fault reset command cycles power to the switch, in
an attempt to clear a faulted state. If on the fourth unsuccessful attempt to lock
the switch, an inspect flag is set. This flag can be used to inform the operator to
inspect the tap, the switch, and its cabling.
You can change the number of attempts and the delay that is allowed before
determining the lock command does not work. The delay must be set for at least
200 ms.