Yokogawa AXFA14G/C - Manual (Page 88)

IM 01E20F02-01E A-29
APPENDIX 4. LINK MASTER FUNCTIONS
A4.5.2 Descriptions for LM Parameters
The following describes LM parameters of an AXF
transmitter.
NOTE: Do not turn off the power to the AXF for 60 seconds after
making a change to its parameter settings.
(1)DlmeLinkMasterCapabilitiesVariable
Meaning
Bit
Position
Value Description
1
0
0
LAS Schedule
in Non-volatile
Memory
Last Values
Record
Supported
Link Master
Statistics
Record
Supported
Whether the LAS schedule can
(= 1) or cannot (= 0) be saved
to the non-volatile memory
Whether to support (= 1) or
not to support (= 0)
LastValuesRecord.
Whether to support (= 1) or
not to support (= 0)
DlmeLinkMasterStatisticsRecord.
B3: 0x04
B2: 0x02
B1: 0x01
TA0406.EPS
(2)DlmeLinkMasterInfoRecord
Element
Sub-
index
Descrip-
tion
Size
[bytes]
1
2
2
2
2
4
2
2
V(MSO)
V(DMDT)
V(DTHT)
V(TTRT)
V(LTHT)
V(TDP)
V(MICD)
V(LDDP)
MaxSchedulingOverhead
DefMinTokenDelegTime
DefTokenHoldTime
TargetTokenRotTime
LinkMaintTokHoldTime
TimeDistributionPeriod
MaximumInactivityToClaimLasDelay
LasDatabaseStatusSpduDistributionPeriod
1
2
3
4
5
6
7
8
TA0407.EPS
(3)PrimaryLinkMasterFlagVariable
Explicitly declares the LAS. Writing “true” (0xFF) to
this parameter in a device causes that device to attempt
to become the LAS. However, a request of writing
“true” to this parameter in a device is rejected if the
value of the same parameter in any other device that
has a smaller node address within the same segment is
true.
(4)LiveListStatusArrayVariable
A 32-byte variable, in which each bit represents the
status of whether a device on the same segment is live
or not. The leading bit corresponds to the device
address 0x00, and final bit to 0xFF. The value of
LiveListStatusArrayVariable in the case where devices
having the addresses 0x10 and 0x15 in the fieldbus
segment is shown below.
0x00 00 84 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
Bit correspondences: 0 0 0 0 0 0 0 0 0 0 0
0
ϫ00
0 0 0 0 0 1 0 0 0 0 1 0 0...
0
ϫ10 0ϫ15
(5)MaxTokenHoldTimeArray
An 8(64 byte array variable, in which each set of 2
bytes represents the delegation time (set as an octet
time) assigned to a device. The delegation time
denotes a time period that is given to a device by
means of a PT message sent from the LAS within each
token circulation cycle.
The leading 2 bytes correspond to the device address
0x00, and the final 2 bytes to the device address 0xFF.
Specify the subindex to access this parameter.
(6)BootOperatFunctionalClass
Writing 1 to this parameter in a device and restarting
the device causes the device to start as a basic device.
On the contrary, writing 2 to this parameter and
restarting the device causes the device to start as an
LM.
(7)CurrentLinkSettingRecord and
ConfiguredLinkSettingsRecord
CurrentLinkSettingRecord indicates the bus parameter
settings currently used. ConfiguredLinkSettingsRecord
indicates the bus parameter settings to be used when
the device becomes the LAS. Thus, when a device is
the LAS, its CurrentLinkSettingRecord and
ConfiguredLinkSettingsRecord have the same values.
Element
Sub-
index
Descrip-
tion
Size
[bytes]
2
1
1
1
2
1
1
1
1
1
1
V(ST)
V(PhLO)
V(MRD)
V(FUN)
V(TL)
V(MID)
V(NUN)
V(PhPE)
V(PhGE)
V(PhIS)
V(TSC)
SlotTime
PerDlpduPhlOverhead
MaxResponseDelay
FirstUnpolledNodeId
ThisLink
MinInterPduDelay
NumConsecUnpolledNodeId
PreambleExtension
PostTransGapExtension
MaxInterChanSignalSkew
TimeSyncClass
1
2
3
4
5
6
7
8
9
10
11
TA0408.EPS