GE 845 Instruction Manual page 172

DEVICE
4–68
buffer space can be monitored to produce an alarm when the logged data occupies
80% of the data logger storage space. Target message, and operand "Data Logger
ALRM" is generated at this time.
TRIGGER
Range: Off, Any FlexLogic operand
Default: Off
This setting selects the signal used to trigger the start of a new data logger record. Any
FlexLogic operand can be used as a trigger source. The Triggered setting only applies
when the Data Logger Function is set to "Triggered".
TRIGGER POSITION
Range: 0 to 50% steps of 1%
Default: 20%
This setpoint defines the percentage of buffer space that is used for recording pre-
trigger samples.
RATE
Range: 1 cycle, 1 second, 30 seconds, 1 minute, 15 minutes, 30 minutes, 1 hour
Default: 1 minute
This setting selects the time interval at which the actual value is recorded.
CHANNEL 1(16) SOURCE
Range: Off, Any FlexAnalog parameter
Default: Off
This setpoint selects the metering analog value that is to be recorded in Channel 1(16) of
the data log. The parameters available in a given relay are dependent on: the type of
relay, the type and number of CT/VT hardware installed, and the type and number of
Analog Inputs hardware installed. Upon startup, the relay automatically prepares the
parameter list.
CHANNEL 1(16) MODE
Default: Sample
Range: Sample, Min, Max, Mean
This setpoint defines the type of sample to be logged in the data logger record with
respect to the selected rate, i.e the time interval selected under the setpoint "Rate".
While enabled the Data Logger executes every protection pass and each of the four
modes —Sample, Max, Min or Mean. The flexanalog values are updated at protection-
pass rate:
In "Sample" mode the data logger records the flexanalog value updated in the first
protection-pass from the time interval selected under setpoint "Rate".
In "Max" mode the data logger records the maximum protection pass value of the
selected flexanalog parameter from all protection pass values from the time interval
selected under setpoint "Rate".
In "Min" mode the data logger records the minimum protection pass value of the
selected flexanalog parameter from all protection pass values from the time interval
selected under setpoint "Rate".
In "Mean" mode, the data logger records the average value among all the values at
protection-pass rate, from the time interval selected under setpoint "Rate".
The mean (average) is calculated simply using the well known ratio between the sum of
all the values and their number over the time interval.
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS