Yokogawa EJX930A - Manual (Page 134)

<Appendix 6. Link Master Functions>
A6-6
IM 01C25T02-01E
A6.5.2 Descriptions for LM Parameters
The following describes LM parameters of the
transmitter.
NOTE: Do not turn off the power to the transmitter for 60
seconds after making a change to its parameter
settings.
(1) DlmeLinkMasterCapabilitiesVariable
Bit
Position
Meaning Description Value
B3: 0x04 LAS
Schedule in
Non-volatile
Memory
Whether the LAS schedule
can (=1) or cannot (=0) be
saved to the non-volatile
memory
1
B2: 0x02 Last Values
Record
Supported
Whether to support (=1)
or not to support (=0)
LastValuesRecord.
0
B1: 0x01 Link Master
Statistics
Record
Supported
Whether to support (=1)
or not to support (=0)
DlmeLinkMasterStatisticsRecord.
0
(2) DlmeLinkMasterInfoRecord
Sub-
index
Element
Size
[bytes]
Descrip-
tion
1 MaxSchedulingOverhead 1 V(MSO)
2 DefMinTokenDelegTime 2 V(DMDT)
3 DefTokenHoldTime 2 V(DTHT)
4 TargetTokenRotTime 2 V(TTRT)
5 LinkMaintTokHoldTime 2 V(LTHT)
6 TimeDistributionPeriod 4 V(TDP)
7 MaximumInactivityToClaimLasDelay 2 V(MICD)
8 LasDatabaseStatusSpduDistributionPeriod 2 V(LDDP)
(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...
0Ч00
0Ч10 0Ч15
(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.