GE P24DM, Technical Manual

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Many of the IED’s functions are configurable so some of the Object 10 commands described in the following
sections may not be available. A read from Object 10 reports the point as off-line and an operate command to
Object 12 generates an error response.
Examples of Object 10 points that maybe reported as off-line are:
● Activate setting groups: Ensure setting groups are enabled
●
CB trip/close: Ensure remote CB control is enabled
● Reset NPS thermal: Ensure NPS thermal protection is enabled
●
Reset thermal O/L: Ensure thermal overload protection is enabled
● Reset RTD flags: Ensure RTD Inputs is enabled
●
Control inputs: Ensure control inputs are enabled
6.3.4 OBJECT 20 BINARY COUNTERS
Object 20, binary counters, contains cumulative counters and measurements. The binary counters can be read as
their present ‘running’ value from Object 20, or as a ‘frozen’ value from Object 21. The running counters of object
20 accept the read, freeze and clear functions. The freeze function takes the current value of the object 20 running
counter and stores it in the corresponding Object 21 frozen counter. The freeze and clear function resets the Object
20 running counter to zero after freezing its value.
Binary counter and frozen counter change event values are available for reporting from Object 22 and Object 23
respectively. Counter change events (Object 22) only report the most recent change, so the maximum number of
events supported is the same as the total number of counters. Frozen counter change events (Object 23) are
generated whenever a freeze operation is performed and a change has occurred since the previous freeze
command. The frozen counter event queues store the points for up to two freeze operations.
6.3.5 OBJECT 30 ANALOGUE INPUT
Object 30, analogue inputs, contains information from the IED’s measurements columns in the menu. All object 30
points can be reported as 16 or 32-bit integer values with flag, 16 or 32-bit integer values without flag, as well as
short floating point values.
Analogue values can be reported to the master station as primary, secondary or normalized values (which takes
into account the IED’s CT and VT ratios), and this is settable in the COMMUNICATIONS column in the IED.
Corresponding deadband settings can be displayed in terms of a primary, secondary or normalized value.
Deadband point values can be reported and written using Object 34 variations.
The deadband is the setting used to determine whether a change event should be generated for each point. The
change events can be read using Object 32 or Object 60. These events are generated for any point which has a
value changed by more than the deadband setting since the last time the data value was reported.
Any analogue measurement that is unavailable when it is read is reported as offline. For example, the frequency
would be offline if the current and voltage frequency is outside the tracking range of the IED. All Object 30 points
are reported as secondary values in DNP 3.0 (with respect to CT and VT ratios).
6.3.6 OBJECT 40 ANALOGUE OUTPUT
The conversion to fixed-point format requires the use of a scaling factor, which is configurable for the various
types of data within the IED such as current, voltage, and phase angle. All Object 40 points report the integer
scaling values and Object 41 is available to configure integer scaling quantities.
6.3.7 OBJECT 50 TIME SYNCHRONISATION
Function codes 1 (read) and 2 (write) are supported for Object 50 (time and date) variation 1. The DNP Need Time
function (the duration of time waited before requesting another time sync from the master) is supported, and is
configurable in the range 1 - 30 minutes.
P24xM Chapter 16 - Communications
P24xM-TM-EN-2.1 327