1 historical database and event & alarm log – Emerson ROC827 User Manual
Page 17
ROC827 Instruction Manual
Issued Mar-06
General Information
1-11
The difference between 16-point and 8-point addressing becomes critical
when you have a host device reading data from specific TLPs. For
example, under 16-point addressing, channel 2 for a DI module in slot 2 is
referenced by TLP 101,33,3. Under 8-point addressing, channel 2 for a DI
module in slot 2 is referenced by TLP 101,17,23. Table 1-2 illustrates the
difference between 8-point and 16-point addressing.
Table 1-2. 16-Point vs. 8-Point Addressing
Slot Number
Logicals (16 pt)
Logicals (8 pt)
0 0–15 0–7
1 16–31
8–15
2 32–47
16–23
3 48–63
24–31
4 64–79
32–39
5 80–95
40–47
6 96–111
48–55
7 112–127
56–63
8 128–143
64–71
9 144–159
72–79
10 N/A
80–87
11 N/A
88–95
12 N/A
96–103
13 N/A
104–111
14 N/A
112–119
15 N/A
120–127
16 N/A
128–135
17 N/A
136–143
18 N/A
144–151
19 N/A
152–159
20 N/A
160–167
21 N/A
168–175
22 N/A
176–183
23 N/A
184–191
24 N/A
192–199
25 N/A
200–207
26 N/A
208–215
27 N/A
216–223
Note
: 16-point addressing is the default for the ROC800-Series firmware.
To maximize the expanded input capabilities of the ROC827, you must
use ROCKLINK 800 to modify the firmware addressing to use 8-points
per module.
1.4.1 Historical Database and Event & Alarm Log
The historical database provides archiving of measured and calculated
values for either on-demand viewing or saving to a file. It provides an
historical record in accordance with API Chapter 21.1. You can configure
each of up to 200 points in the historical database to archive values under
various schemes, such as averaging or accumulating, as appropriate for the
type of database point.