GE Power Quality Meter Series Instruction Manual page 238

8.1 DNP 3.0 PROTOCOL
The following restrictions should be observed when using object 12 to control the points listed in the following
table.
1. The Count field is checked first. If it is zero, the command will be accepted but no action will be taken. If
this field is non-zero, the command will be executed exactly once regardless of its value.
2. The Control Code field of object 12 is then inspected:
• A NUL Code will cause the command to be accepted without any action being taken.
• A Code of "Pulse On" (1) is valid for all points. This is used to activate the function (e.g., Reset) associated
with the point.
• All other Codes are invalid and will be rejected.
• The Queue, Clear, and Trip/Close sub-fields are ignored.
3. The On Time and Off Time fields are ignored. A "Pulse On" Code takes effect immediately when received.
Thus, the timing is irrelevant.
4. The Status field in the response will reflect the success or failure of the control attempt thus:
• A Status of "Request Accepted" (0) will be returned if the command was accepted.
• A Status of "Request not Accepted due to Formatting Errors" (3) will be returned if the Control Code field
was incorrectly formatted or an invalid Code was present in the command.
• A Status of "Control Operation not Supported for this Point" (4) will be returned in response to a "Latch On"
or "Latch Off" command
5. An operate of the Reset, alarm relay on/off or Aux Relay 1-3 on/off points may fail (even if the command is
accepted) due to other inputs or conditions (e.g., alarm conditions) existing at the time. To verify the suc-
cess or failure of an operate of these points it is necessary that the associated Binary Input(s) be examined
after the control attempt is performed.
6. When using object 10 to read the status of a Binary Output, a read will always return zero.
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8-8 PQM Power Quality Meter
8 DNP COMMUNICATIONS
GE Power Management