Yokogawa FVX110 - Manual (Page 149)

<Appendix 7. Link Master Functions>
A7-2
IM 01S01C01-01EN
A7.3 Transfer of LAS
There are two procedures for an LM to become the LAS:
• If the LM whose value of [V(ST)×V(TN)] is the smallest on a segment, with the exception of the current
LAS, judges that there is no LAS on the segment, in such a case as when the segment has started up or
when the current LAS has failed, the LM declares itself as the LAS, then becomes the LAS. (With this
procedure, an LM backs up the LAS as shown in the following figure.)
• The LM whose value of [V(ST)×V(TN)] is the smallest on a segment, with the exception of the current LAS,
requests the LAS on the same segment to transfer the right of being the LAS, then becomes the LAS.
LM
Node address:
0x15
SlotTime = 5
LM
Node address:
0x16
SlotTime = 5
Node address: 0x14
SlotTime = 5
Basic device
Node address:
0xF1
Basic device
Node address:
0xF2
Basic device
Node address:
0xF3
Basic device
Node address:
0xF4
LAS
LAS
In the event that the current LAS in
this segment (node address 0x14)
fails, the LM with the address of 0x15
takes its place to become the LAS.
LM
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Figure A7.2 Backup of LAS
To set up an FVX110 as a device that is capable of backing up the LAS, follow the procedure below.
NOTE: When changing the settings in an FVX110, add the FVX110 to the segment in which an LAS is running.
After making changes to the settings, do not turn off the power to the FVX110 for at least 30 seconds.
(1) Set the node address of the FVX110. In general, use an address from 0x10 to [V(FUN) - 1].
Not used
LM device
Not used
Basic device
Default address
Portable-device address
V (FUN)
V (FUN) + V (NUN)
V (NUN)
0xFF
0xFC
0xFB
0xF8
0xF7
0x00
FA0703.ai
0x0F
0x10
0x13
0x14
Bridge device
Figure A7.3 Node Address Ranges