Rockwell Automation T8xxx Trusted Communications Interface - Manual (Page 34)

Trusted
TM
Communication Interface T8151B
Issue 21 Apr 10 PD-T8151B 34
Statistics Mode Control Variable Value Result
Max Scan Rate
False
→
True (Boolean)
0
→
non-zero (Integer)
Max value will remain until next cycle
completed.
Max value then updated with time of next
complete cycle.
True
→
False (Boolean)
non-zero
→
0 (Integer)
Triggers a reset
Scan Rate
False
→
True (Boolean)
0
→
non-zero (Integer)
No effect (data updated every cycle)
True
→
False (Boolean)
non-zero
→
0 (Integer)
No effect (data updated every cycle)
Average
False
→
True (Boolean)
0
→
non-zero (Integer)
Average value will remain until next cycle
completed.
Average value then updated with time of
next complete cycle.
True
→
False (Boolean)
non-zero
→
0 (Integer)
Triggers a reset
Table 13 Modbus Statistics Control
The slave poll scan is defined as the time taken to poll a slave for all messages in the poll list. The first
message defined in the poll list is taken as the start and end point of the timing sequence. This is
illustrated in the diagram Figure 14 below.
Sequence No. Message
1 Slave 1 Msg 1
2 Slave 2 Msg 1
3 Slave 3 Msg 1
4 Slave 1 Msg 2
5 Slave 2 Msg 2
6 Slave 3 Msg 2
7 Slave 1 Msg 3
8 Slave 2 Msg 1
9 Slave 3 Msg 3
10 Slave 1 Msg 4
11 Slave 2 Msg 2
12 Slave 3 Msg 1
13 Slave 1 Msg 1
14 Slave 2 Msg 1
15 Slave 3 Msg 2
Figure 14 Slave Poll timing
Slave 1
Tstart
Slave 1
Tstop
Slave 3
Tstop
Slave 2
Tstop
Slave 2
Tstart Slave 3
Tstart