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6.6 Remote Operation
6.6.4 Remote latch clear
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FUNCTIONS
6.6.4 Remote latch clear
(1) Definition of Remote Latch Clear
Remote latch clear resets the latched device data from GX Developer or similar
device when the CPU module is in the STOP status.
(2) Applications of remote latch clear
Remote latch clear is useful when the CPU module is in the following areas. In these
cases, the operations are performed in combination with the remote RUN/STOP.
• When the CPU module is at a position out of reach
• When externally performing latch clear of the CPU module inside a control panel.
(3) Remote Latch Clear Method
Remote latch clear can be executed by performing operation from GX Developer,
external device using MC protocol or similar device.
To perform the remote latch clear, follow the following steps:
• Use the remote STOP to bring the CPU module to STOP status.
• Use the Latch Clear to bring the CPU module to the Latch Clear status.
Operate GX Developer by choosing [Online] [Remote operation].
Use the MC protocol command to execute control from an external device using
the MC protocol.
Q Corresponding MELSEC Communication Protocol Reference Manual
• To return the High Performance model QCPU to RUN status after the remote
latch clear, perform a remote RUN operation.
(4) Precautions
(a) Latch clear in RUN status
Latch clear cannot be performed when the CPU module is in the RUN status.
(b) Range where latch clear operation is enabled/disabled
The latch clear operation can be set to be enabled/disabled for the device latch
range in the device setting of the PLC parameter dialog box.
Remote latch clear operation resets only the device range set as the "latch (1)"
range.
Refer to Section 3.7 (2)(c) for how to reset the device set as latch clear disabled.
