ProSoft Technology PTQ-PDPMV1 - Manual (Page 201)

PTQ-PDPMV1 ♦ Quantum Platform Hot Standby Support
PROFIBUS DP Master Network Interface Module for Quantum User Manual
ProSoft Technology, Inc. Page 201 of 306
August 12, 2014
7.3 PTQ-PDPMV1 Operation
While in Primary mode, the module will read the output area and write the input
area. The module will constantly scan the HSBY control word to determine the
HSBY state.
 Active LED will flash if the module is in Standby mode in a Hot Standby
system. The Hot Standby Status Word of the Modicon Quantum processor is
read during each end-of-scan.
 During switchover caused by a failure on the primary, all PROFIBUS I/Os will
be held at their last values, until the moment the new PTQ takes control (no
glitch on I/O devices).
7.3.1 PTQ-PDPMV1 HSBY Diagnostic Data
PTQ Input Data Block
The PTQ module reports the HSBY Local and Remote Status Registers via the
Input Data Block.
Input Data Block (HSBY words only)