ProSoft Technology PTQ-PDPMV1 - Manual (Page 199)

PTQ-PDPMV1 ♦ Quantum Platform Hot Standby Support
PROFIBUS DP Master Network Interface Module for Quantum User Manual
ProSoft Technology, Inc. Page 199 of 306
August 12, 2014
7.2.9 Crossed Status Information
The ping message communicates status information between the active and
remote (passive) Masters, and vice versa.
A part of this "crossed status information" (CSI) would be presented in the "HSBY
Remote status"-/"HSBY Nr of remote slaves" registers located in the fieldbus
specific area of the DPRAM.
These registers would be updated every time new status information is received
from the counterpart. Polling for new status information takes place every TA ms.
Normally, the application would forward this information to a high-level system
(for example, application of the primary PLC), which in turn would determine if a
switchover should be carried out, or not.
The following illustration shows how CSI is communicated between the two
Masters and how it is displayed in the fieldbus specific area of the DPRAM.