Yokogawa digitalYEWFLO (DY-FF) - Manual (Page 125)

<APPENDIX 7. LINK MASTER FUNCTIONS>
A7-8
IM 01F06F00-01EN
(14) DlmeScheduleDescriptor
This parameter exists for the same number as the
total number of domains, and each describes the
LAS schedule downloaded to the corresponding
domain. For the domain to which a schedule
has not yet been downloaded, the values in this
parameter are all zeros.
Sub-
index
Element
Size
[bytes]
Description
1 Version 2 Indicates the version number of
the LAS schedule downloaded
to the corresponding domain.
2 Macrocycle
Duration
4 Indicates the macro cycle of the
LAS schedule downloaded to
the corresponding domain.
3 TimeResolution 2 Indicates the time resolution that
is required to execute the LAS
schedule downloaded to the
corresponding domain.
(15) Domain
Read/write: impossible; get-OD: possible
Carrying out the GenericDomainDownload
command from a host writes an LAS schedule to
the domain.
A7.6 Trouble Shooting
Q1. When the LAS stops, a digitalYEWFLO
does not back it up by becoming the LAS.
Why?
A1-1. Is that digitalYEWFLO 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 confi rm that the
following condition is met:
digitalYEWFLO Other LMs
V(ST) × V(TN) < V(ST) × V(TN)
Q2. How can I make a digitalYEWFLO become
the LAS?
A2-1. Check that the version numbers of the
active schedules in the current LAS and the
digitalYEWFLO are the same by reading:
LinkScheduleListCharacteristicsRecord
(index 374 for a digitalYEWFLO)
- ActiveScheduleVersion (subindex 3)
A2-2. Make the digitalYEWFLO 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 digitalYEWFLO.
Q3. On a segment where a digitalYEWFLO
works as the LAS, another device cannot
be connected. Why?
A3-1. Check the following bus parameters that
indicate the bus parameter as being the LAS
for the digitalYEWFLO and the capabilities of
being the LAS for the device that cannot be
connected:
• V(ST), V(MID), and V(MRD) of
digitalYEWFLO:
Confi guredLinkSettingsRecord (index
369)
• V(ST), V(MID), and V(MRD) of
problematic device: DlmeBasicInfo
Then, confi rm that the following conditions
are met:
digitalYEWFLO Problematic Device
V(ST) > V(ST)
V(MID) > V(MID)
V(MRD) > V(MRD)
A3-2. Check that the node address of the
problematic device does not lie within
either 0x00 to 0x10 or the range of unused
(unpolled) node addresses determined by
the digitalYEWFLO’s LM parameter settings,
which is 0x00 to 0x10 or V(FUN) to V(FUN)
+ V(NUM). (Refer to Section 5.2 “Network
Defi nition.”)
Q4. The LCD keeps showing “— — —”. It
is presumed that an LAS does not exist
on the bus or the digitalYEWFLO cannot
establish communication with the LAS.
What should be done?
A4-1. Check that an LAS is connected on the bus.
(When using the digitalYEWFLO as the LAS
[which requires an option], perform steps (1)
to (3) in APPENDIX 7.3 “Transfer of LAS.”)