User Manual

<Appendix 5. Link Master Functions>
A5-9
IM 01C50T02-01E
A5.6 FAQs
Q1. When the LAS stops, a YTA does not back
it up by becoming the LAS. Why?
A1-1. Is that YTA 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 conrm that the
following condition is met:
YTA Other LMs
V(ST)×V(TN) < V(ST)×V(TN)
Q2. How can I make a YTA become the LAS?
A2-1. Check that the version numbers of the active
schedules in the current LAS and the YTA
are the same by reading:
LinkScheduleListCharacteristicsRecord
(index 374 for a YTA)
- ActiveScheduleVersion (subindex 3)
A2-2. Make the YTA 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 YTA.
Q3. On a segment where a YTA 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 YTA and the capabilities of being the
LAS for the device that cannot be connected:
• V(ST), V(MID), V(MRD) of YTA:
ConguredLinkSettingsRecord (index 369)
• V(ST), V(MID), V(MRD) of problematic
device: DlmeBasicInfo
Then, conrm that the following conditions
are met:
YTA 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 YTA.
Q4. “-----” are shown on the LCD of YTA.
Followings are possible causes; No LAS
existing on the network, no communication
being established between YTA and LAS, or AI
Block not being correctly scheduled
A4-1. Check that LAS is correctly connected to the
network.
(If YTA is used as LAS, follow the procedures
shown in A5.3 (1), (2) and (3))
A4-2. Check that LAS parameters are set so as to
meet the YTA’s requirement.
(See also 5.2 Network Conguration)
LAS YTA
V(ST) > V(ST) (4 or greater)
V(MID) > V(MID) (4 or greater)
V(MRD) > V(MRD) (3 or greater)
A4-3. Check that the node address of YTA
is correctly set. (See also 5.2 Network
Conguration)
The address should be set as follows.
• Not in the range between V(FUN) and
V(FUN)+V(NUM) of LAS.
• Not in the range of default address.
A4-4. Check that the AI block dened in the
DISPLAY_AI_OUT of the transducer block is
correctly scheduled.