IM 01C22T02-01E
A-26
APPENDIX 5. Link Master Functions
A5.4 LM Functions
No.
Function
Description
LM initialization
Startup of other
nodes (PN and
Node Activation
SPDU
transmissions)
PT transmission
(including final bit
monitoring)
CD transmission
Time synchronization
Domain download
server
Live list equalization
LAS transfer
Reading/writing of
NMIB for LM
Round Trip Delay
Reply (RR)
Reply to DLPDU
Long address
1
2
3
4
5
6
7
8
9
10
11
TA0504.EPS
When a fieldbus segment starts,
the LM with the smallest [V(ST)
×
V(TN)] value within the segment
becomes the LAS.
At all times, each LM is checking
whether or not a carrier is on the
segment.
Transmits a PN (Probe Node)
message, and Node Activation
SPDU message to devices which
return a new PR (Probe Response)
message.
Passes a PT (Pass Token)
message to devices included in the
live list sequentially, and monitors
the RT (Return Token) and final bit
returned in reply to the PT.
Transmits a CD (Compel Data)
message at the scheduled times.
Supports periodic TD (Time
Distribution) transmissions and
transmissions of a reply to a CT
(Compel Time).
Sets the schedule data.
The schedule data can be
equalized only when the Domain
Download command is carried out
from outside the LM in question.
(The version of the schedule is
usually monitored, but no action
takes place, even when it changes.)
Transmits SPDU messages to LMs
to equalize live lists.
Transfers the right of being the LAS
to another LM.
See Section A5.5.
Not yet supported in the current
version.
Not yet supported in the current
version.
