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1 historical database and event & alarm log – Emerson ROC827 User Manual

Page 17

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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.