ProSoft Technology PTQ-PDPMV1 - Manual (Page 213)

PTQ-PDPMV1 ♦ Quantum Platform Hot Standby Support
PROFIBUS DP Master Network Interface Module for Quantum User Manual
ProSoft Technology, Inc. Page 213 of 306
August 12, 2014
Highest Station Address (HSA)
HSA defines the highest address that a Master can have to be included in the
token ring. For example, a Master with address 35 will not be included in the
token ring if the HSA is set to 34.
It is recommended to keep the HSA as low as possible since it affects the time it
takes for a Master to enter the token ring.
Master Address (TS)
The address of the remote (passive) Master would be derived by subtracting one
(-1) from bus parameter "TS" (This Station). For example, if TS in the database
equals 2, the remote (passive) Master would use address 1. If TS in the
database equals 0 it would use address 125.
During switchover, when the remote (passive) Master becomes active, the
address would equal TS. Please note that this is handled by the Master module
internally; the database downloaded to the two Masters must be identical.
It is preferable to keep the address of the remote (passive) Master as low as
possible since it affects the time it takes to detect a faulty local (active) Master.
A problem with setting TS = 0 is that the remote (passive) Master would be
assigned address 125, which in turn means that HSA must be set to its maximum
value of 125 to allow the remote (passive) Master to enter the token ring. If not,
the Master module will reject mailbox END_INIT (Fault info = 6 and Additional
Fault info = 19).
This special case is handled by the PCB Master configuration, which will not
accept TS = 0 if the "HSBY" bus parameter profile is selected.
7.3.4 HSBY Master GSD File
No changes to the original file PTQ_18F0.GSD would be necessary.
7.3.5 LED Indicators
 The Master status LED would flash red, indicating that the Master module is
operating as a remote (passive) Master.
 When the Master module operates as a remote (passive) Master, the COM-
status LED signals the same information as it does for a local (active) Master,
or a combined C1/C2 Master.