Rockwell Automation Guardmaster 440R-ENETR, Руководство пользователя, Страница: 67 / 86

Rockwell Automation Publication 440R-UM009C-EN-P - July 2019 67
Studio 5000 Example Logix Code Chapter 8
Fault Reset Command to All GuardLink Taps
The fault reset command is used to power cycle a tap. In GuardLink 1.0, the DG
relay does not know if a device connected to a tap is in a faulted state; the DG
relay only knows that the tap is OFF. If the tap remains OFF, this state can
indicate a device fault. A fault reset command can be sent to the tap to power
cycle the tap and the device that is connected to the tap. This action can clear the
fault in the device.
The fault reset command cannot be sent to all taps with a rung of code like the
lock all and unlock all commands. By using timers, logic can be written to execute
the fault reset command to all taps.
Figure 52 on page 68 shows example logic for Studio 5000. A reset command is
sent to a tap. After 3 seconds, the reset command is sent to the next tap. The
process is repeated until all taps are reset.
In this example, a momentary push button is used to initiate the subroutine. The
FRC_0 output is latched; this output is for the first tap (Tap 0). The output
starts a timer. The timer value is set to 3000 ms; enough time for the tap to
execute its startup self-test. After timer is done, the FRC_0 output is unlatched,
and the FRC_1 output is latched. The steps are repeated for each tap.