7-3
QHysteresis combination uses comparison 1 to set the combination, and comparison 2 to clear the
combination. If both inputs are asserted, comparison 1 has priority. The usual arrangement would be
to program comparison 1 to above a large value and comparison 2 to below a small value. When the
monitored value goes above comparison 1, the combination will be set to a 1, until the
monitored value goes below comparison 2, when the combination will be cleared to a 0.
Pollable information would consist of:
32 bits Comparison 1 states for 32 limits
32 bits Comparison 2 states for 32 limits
32 bits Combination states for 32 limits
Total of 96 bits (12 bytes)
7.3: Historical Log Settings Block (45205-45464)
Historical Log 1 Data Pointers (45205 - 45332), Historical Log 2 Data Pointers (45333 - 45460).
QThese registers indicate which information to include in a record in the Historical Log. Each Data
Pointer has the following 4 (four) byte structure:
QALine Number is an index into the Communication Table. Example: Line Number 11 is for the
12th line in the Communication Table, 0.1 second Phase-to-Neutral Voltages. Data Pointers with
Line Numbers greater than the number of lines in the table are ignored.
QAPoint Number is an index into a Line in the Communication Table. Example: Point Number 1 is
for the second entry in a Line. Line Number 11, Point Number 1 is the 2nd in the 12th line, 0.1
second VBN. Data Pointers with Point Numbers greater than the number of points for the line are
ignored.
Snapshot Interval for Historical Log 1 (45361), for Historical Log 2 (45462).
One register, 2 byte unsigned integers ranged from 0 to 3600.
The unit is 1 Second.
Historical Log 1 Record Size (45463), Historical Log 2 Record Size (45464).
This register is an enumeration for the size of a record in the Historical Log. The valid values are:
0x00000 = 32 byte records 0x00002 = 128 byte records 0x00004 = 16 byte records
0x00001 = 64 byte records 0x00003 = 256 byte records
Data Pointer 4-Byte Structure
Size Format Description
2 byte Unsigned Integer Line Number
1 byte Unsigned Character Point Number
1 byte Unsigned Character Reserved