Mitsubishi Electric QJ71E71-100 User Manual page 219

(3) Issuing a system switching request upon disconnection detection
The E71 mounted on the control system CPU module monitors the connection status of the cable connected to
the E71, and on detection of disconnection, it issues a system switching request to the control system CPU
module. Disconnection is detected in the following cases.
• Disconnection between the E71 and a hub
• Cable removal from the hub side connector
• Hub power-off
• Cable removal from the E71 side connector
Remark
This function is available for the QJ71E71-100 only.
(a) System switching request operation
The E71 always monitors the connected cable for disconnection.
Connected device
Disconnected
Control system (system A)
Tracking cable
Control system (system A)
Tracking cable
System switching request
Standby system (system B)
Connected device
Standby system (system B)
1.
Disconnection monitoring
The E71 always monitors the connected cable for
*1
disconnection. The monitoring result is stored to the
buffer memory area, Hub connection status area
(address: C9 ).
H
2.
Upon disconnection detection
If the E71 mounted with the control system CPU module
detects disconnection, it performs a disconnection
status time check. If the disconnected status continues
for the period of the disconnection detection monitoring
time, the E71 issues a system switching request to the
control system CPU module.
CHAPTER 14 OTHER FUNCTIONS
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