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MELSEC-F
COMMUNICATION PROCEDURE5
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5.8 Hub Connection Status Monitor Function
The current connection status of the Ethernet module and hub, the transmission
speed, and the number of times the Ethernet module detected disconnection can be
checked at the following buffer memory addresses.
(1) Hub connection status area (BFM#201)
Stores the current connection status of the FX3U-ENET-L and hub and the
transmission speed.
(2) Disconnection detection count storage area (BFM#20995)
(a) Stores the number of disconnection detection times after initial processing is
completed.
Disconnection is detected in any of the following cases.
• Disconnection between Ethernet module and hub
• Cable removal from hub side connector
• Hub power-off
• Cable removal from Ethernet module side connector
(b) If an error has occurred 65536 times or more, a count stops at FFFFH
(65535).
Write "0" to this area using a sequence program to clear the stored value.
Ethernet module
Hub
External device
10BASE-T/100BASE-TX,
Full duplex/half duplex
b15 b14
BFM#201
b13 b11 b10 b9 b8 b0
1) Communication mode
0: Half duplex
1: Full duplex
2) Hub connection status
0: Hub not connected/disconnected
1: Hub connected
3) Data transmission speed
0: Operating at 10BASE-T
1: Operating at 100BASE-TX
1)2)3)
(Bits other than above are reserved for system use.)
*1 When a switching hub is used, it may not be displayed correctly.
*1