ProSoft Technology PTQ-PDPMV1 - Manual (Page 196)

Hot Standby Support PTQ-PDPMV1 ♦ Quantum Platform
User Manual PROFIBUS DP Master Network Interface Module for Quantum
Page 196 of 306 ProSoft Technology, Inc.
August 12, 2014
Calculated Times for Detecting a Missing Counterpart
Baud Rate TA[ms] TP[ms] TFA[ms]
12 Mbps

T
TR
= 50 ms, T
SL
= 1000 Tbits 55 ≤ T
TR
1
1.5 Mbps

T
TR
= 186 ms, T
SL
= 300 Tbits 205 2
500 kbps

T
TR
= 500 ms, T
SL
= 200 Tbits 550 4
93.75 kbps (PA)

T
TR
= 2374 ms, T
SL
= 100 Tbits 2611 9
45.45 kbps (PA)

T
TR
= 14000 ms, T
SL
= 640 Tbits 15400 113
9.6 kbps

T
TR
= 23200 ms, T
SL
= 100 Tbits 25520 83
Ping Sequence
This section shows the ping sequence, and how the COM-bit in register "HSBY
Remote status" is affected under different scenarios.
The figures show the active and the remote (passive) Masters connected via the
PROFIBUS network. For each Master, the DPRAM (that is, application interface)
and the software objects that are responsible for the ping sequence are shown.
Start-up
Local (active) Master operational prior to passive
As soon as the local (active) Master is ready to communicate on the PROFIBUS
network, it would start polling for ping messages from the passive one. As soon
as it receives the first ping request, the COM-bit is altered from zero to one.