Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G - Manual (Page 82)

<APPENDIX 5. LINK MASTER FUNCTIONS>
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IM 11M12D01-61E
A5.6 FAQs
Q1. When the LAS stops, a AV550G does not back it up by becoming the LAS. Why?
A1-1. Is that AV550G 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:
AV550G Other LMs
V(ST) 3 V(TN) < V(ST) 3 V(TN)
Q2. How can I make a AV550G become the LAS?
A2-1. Check that the version numbers of the active schedules in the current LAS and the AV550G are
the same by reading:
LinkScheduleListCharacteristicsRecord (index 374 for a AV550G)
- ActiveScheduleVersion (subindex 3)
A2-2. Make the AV550G 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 AV550G.
Q3. On a segment where a AV550G 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
AV550G and the capabilities of being the LAS for the device that cannot be connected:
• V(ST), V(MID), and V(MRD) of AV550G: ConfiguredLinkSettingsRecord (index 369)
• V(ST), V(MID), and V(MRD) of problematic device: DlmeBasicInfo
Then, confirm that the following conditions are met:
AV550G 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 AV550G’s LM parameter
settings, which is 0x00 to 0x10 or V(FUN) to V(FUN) + V(NUM).
(Refer to Section 5.2, “Network Definition.”)