Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G - Manual (Page 74)

A-25
IM 11M12D01-61E
A5.3 Transfer of LAS
There are two procedures for an LM to become the LAS:
• If the LM whose value of [V(ST)3V(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)3V(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.
Figure A5-2. Backup of LAS
To set up a AV550G as a device that is capable of backing up the LAS, follow the procedure below.
NOTE: When changing the settings in a AV550G, add the AV550G to the segment in which an LAS is
running. After making changes to the settings, do not turn off the power to the AV550G for at
least 60 seconds.
(1) Set the node address of the AV550G. In general, use an address from 0x14 to [V(FUN) – 1].
Figure A5-3. Node Address Ranges
(2) In the LAS settings of the AV550V, set the values of V(ST), V(MRD), and V(MID) to the same as the
respective lowest capability values in all the devices within the segment. An example is shown
bellow.
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
FA0602.ai
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
FA0603.ai
0x0F
0x10
0x13
0x14
Bridge device