GE 750 - Page 102

6 - 12 750/760 FEEDER MANAGEMENT RELAY – COMMUNICATIONS GUIDE
ANALOG INPUT / ANALOG INPUT CHANGE CHAPTER 6: DNP POINT LISTS
1. To read a date, read two 16-bit values and interpret these two values using format
F23. The first value provides the month and day and the second value provides the
year.
To read a time, read two 16-bit values and interpret these two values using format
F22. The first value provides the hours and minutes and the second value provides the
milliseconds.
2. Points which have an assigned event class will generate an event object as a result of
any change in the point’s value unless otherwise noted.
3. An event object will be generated if the point’s value changes by a minimum of 2% of
its previous value.
4. An event object will be generated if the system frequency changes by 0.04 Hz or
more.
5. There are two defined maps for Analog Output points. The map that is used is speci-
fied by the setting of the “DNP Point Mapping” setpoint at Modbus address 10DBh.
This setpoint may be set to a value of “Disabled” or “Enabled”. When “Disabled”, only
the preassigned Analog Output points are available beginning at point index 0.
When “Enabled”, the User Map Values are assigned to points 0 through 119 with the
preassigned Analog Outputs following beginning with Point Index 120. The value read
from points 0 through 119 will depend upon the value programmed into the
corresponding User Map Address setpoint (note that programming of these setpoints
can only be accomplished via Modbus). Refer to Accessing Data via the User Map on
page 4-4 for more information.
Please note that changes in User Map Values never generate event objects.
189 309 F3 Last Trip Neutral Voltage Class 1
Table 3: Analog Inputs DNP Points (Sheet 8 of 8)
Index when Point
Mapping is:
Format Description Event
Class
Assigned
Disable
d
Enabled
Table 4: Example Date and Time Interpretation
Example Index
(point mapping
disabled)
Format Example Value
(hexadecimal)
Interpretation Result
Date of
last trip
83 F23 first 16 bits 081D Month = 08
Day = 1D
August 29
84 F23 second 16 bits 07DD Year = 07DD 2013
Time of
last trip
85 F22 first 16 bits 0F3B Hour = 0F
Minute = 3B
3:59 pm
86 F22 second 16 bits 87CC Milliseconds = 87CC 34.764 seconds