Yokogawa YVP110 - Manual (Page 136)

<Appendix 2. Link Master Functions>
A-25
IM 21B04C01-01E
(15) Domain
Read/write: impossible; get-OD: possible
Carrying out the GenericDomainDownload
command from a host writes an LAS schedule to
Domain.
A2.6 FAQs
Q1. When the LAS stops, a YVP does not
back it up by becoming the LAS. Why?
A1-1. Is that YVP running as an LM? Check that
the value of BootOperatFunctionalClass
(index 367) is 2 (indicating that it is an LM).
A1-2. Check the values of V(ST) and V(TN) in all
LMs on the segment and confirm that the
following condition is met:
YVP Other LMs
V(ST)×V(TN) < V(ST)×V(TN)
Q2. How can I make a YVP become the LAS?
A2-1. Check that the version numbers of the active
schedules in the current LAS and the YVP
are the same by reading:
LinkScheduleListCharacteristicsRecord
(index 374 for a YVP)
- ActiveScheduleVersion (subindex 3)
A2-2. Make the YVP declare itself as and become
the LAS by writing:
• 0x00 (false) to
PrimaryLinkMasterFlagVariable in the
current LAS; and
• 0xFF (true) to
PrimaryLinkMasterFlagVariable (index 364)
in the YVP.
Q3. On a segment where a YVP works as
the LAS, another device cannot be
connected. How come?
A3-1. Check the following bus parameters that
indicate the bus parameter as being the LAS
for the YVP and the capabilities of being the
LAS for the device that cannot be connected:
• V(ST), V(MID), V(MRD) of YVP:
ConfiguredLinkSettingsRecord (index 369)
• V(ST), V(MID), V(MRD) of problematic
device: DlmeBasicInfo
Then, confirm that the following conditions
are met:
YVP
Problematic
Device
V(ST) > V(ST)
V(MID) > V(MID)
V(MRD) > V(MRD)
A3-2. Check the node address of the problematic
device is not included in the V(FUN)+V(NUN)
of the YVP.