Mitsubishi Electric CR800 Series Ethernet Function Instruction Manual page 119

3 Description of functions
After the robot slave station has established proper communication with the master station, if the master station goes
down or the wiring becomes disconnected and communication with the master station is blocked, error 7870 is issued
on the robot controller.
The error number of the robot controller and its details can be checked on the error monitor screen of RT ToolBox3.
For the PLC CPU master station, the station with the error can be confirmed in the network status section of the
CC-Link IEF Basic Diagnostics screen in GX Works3.
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