ProSoft Technology MVI56-AFC - Manual (Page 188)

MVI56-AFC Backplane Communication MVI56-AFC ♦ ControlLogix Platform
User Manual Liquid and Gas Flow Computer
Page 188 of 316 ProSoft Technology, Inc.
February 25, 2011
Input Function Block ID
Function Block Name: Meter Analysis
Function Block ID: 11 decimal, 001011 binary, 11264 dec.
Target: Selected Meter Number and Stream Number
Data Block Length: 24 Elements
Total Block Length: 25 Elements
Analysis Precision
This block supplies the analysis for AGA8 and GPA8173 calculations, in high-
precision form as IEEE 32-bit floating point numbers. Upon change of analysis
the meter undergoes a "characterization" calculation, which is performed before
this block is returned; if the analysis has not changed, no characterization is
required, and this block is returned immediately.
The input block always returns an alarm indicator as part of the block id; the
remaining 48 words contain the following information:
Word Description
1 Firmware major and minor version numbers:
Low-order byte: minor version number
High-order byte: major version number
2 Firmware revision number
3 Analysis precision and stream assignment for meter 1 -- Contents of meter-
relative holding register 133 (for meter 1 this is holding register 8133), which is
laid out as follows (also see AFC Manager’s Modbus Dictionary):
Low-order byte: analysis precision:
4 dibits, one for each analysis "slot":
where each dibit has one of these values:
Bits Contents
0, 1 Precision of analysis in slot 0 (Mh00720++)
2, 3 Precision of analysis in slot 1 (Mh00750++)
4, 5 Precision of analysis in slot 2 (Mh00780++)
6, 7 Precision of analysis in slot 3 (Mh00810++)
High-order byte: stream analysis assignment:
Value Precision
0 (00b) (second slot of preceding high-precision)
1 (01b) Low-precision, one slot only
2 (10b) High-precision, two consecutive slots
3 (11b) (illegal value; never occurs)
4 dibits, one for each stream: