A5.5.2 Descriptions For Lm Parameters - YOKOGAWA vigilantplant EJA Series User Manual

A5.5.2 Descriptions for LM Parameters

The following describes LM parameters of an EJA
transmitter.
NOTE: Do not turn off the power to the EJA for 60 seconds after
making a change to its parameter settings.
(1) DlmeLinkMasterCapabilitiesVariable
Bit
Meaning
Position
LAS Schedule Whether the LAS schedule can
B3: 0x04 in Non-volatile (= 1) or cannot (= 0) be saved
Memory
to the non-volatile memory
Last Values Whether to support (= 1) or
B2: 0x02 Record
not to support (= 0)
Supported LastValuesRecord.
Link Master
Whether to support (= 1) or
Statistics not to support (= 0)
B1: 0x01
Record DlmeLinkMasterStatisticsRecord.
Supported
(2) DlmeLinkMasterInfoRecord
Sub-
Element
index
1 MaxSchedulingOverhead
2 DefMinTokenDelegTime
3 DefTokenHoldTime
4 TargetTokenRotTime
5 LinkMaintTokHoldTime
6 TimeDistributionPeriod
7 MaximumInactivityToClaimLasDelay
8 LasDatabaseStatusSpduDistributionPeriod
(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 0 0 0 0 1 0 0 0 0 1 0 0...
0 10
Description Value
1
0
0
TA0506.EPS
Size Descrip-
tion
[bytes]
1 V(MSO)
2 V(DMDT)
2 V(DTHT)
2 V(TTRT)
2 V(LTHT)
4 V(TDP)
2 V(MICD)
2 V(LDDP)
TA0507.EPS
0 00
0 15
(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.
Sub-
Element
index
1 SlotTime
2 PerDlpduPhlOverhead
3 MaxResponseDelay
4 FirstUnpolledNodeId
5 ThisLink
6 MinInterPduDelay
7 NumConsecUnpolledNodeId
8 PreambleExtension
9 PostTransGapExtension
10 MaxInterChanSignalSkew
11 TimeSyncClass
A-29
APPENDIX 5. Link Master Functions
Size
[bytes]
2
1
1
1
2
1
1
1
1
1
1
IM 01C22T02-01E
Descrip-
tion
V(ST)
V(PhLO)
V(MRD)
V(FUN)
V(TL)
V(MID)
V(NUN)
V(PhPE)
V(PhGE)
V(PhIS)
V(TSC)
TA0508.EPS