Function List - Mitsubishi Electric MELSEC-Q series User Manual

3.3

Function list

The following is the function list of the CT input module.
Item
Input range setting
Conversion enable/disable function
Sampling cycle switching function
Sampling processing
Time
average
Digital
Averaging Count
conversion
process average
method
Moving
average
Primary delay filter
Input signal error detection function
Peak current detection function
Dropout function
Scaling function
Process alarm
Warning
output
function
Rate alarm
Maximum value/minimum value hold
function
Logging function
Description
An input range can be selected for each channel depending on a measured
target from the following ranges.
• Factory default ranges (0 to 5AAC, 0 to 50AAC, 0 to 100AAC, 0 to
200AAC, 0 to 400AAC, and 0 to 600AAC)
• User ranges (0 to 5AAC, 0 to 50AAC, 0 to 100AAC, 0 to 200AAC, 0 to
400AAC, and 0 to 600AAC)
Digital conversion can be enabled or disabled for each channel.
A sampling cycle can be selected from 10ms/8CH, 20ms/8CH, 50ms/8CH,
or 100ms/8CH.
CT input values are converted to digital values in each sampling cycle. The
converted values are stored as digital output values in the buffer memory.
Digital conversion is performed for a set time, and a sum of the converted
values except the maximum and minimum values is averaged. The
averaged values are stored in the buffer memory.
Digital conversion is performed the set number of times, and a sum of the
converted values except the maximum and minimum values is averaged.
The averaged values are stored in the buffer memory.
Digital output values for the specified number of times are averaged in
each sampling cycle. The averaged values are stored in the buffer memory.
Depending on the set time constant, digital output values with smoothed
noise can be obtained.
Overrange of a CT input value (excess of a peak value) can be detected.
Since a CT input module can detect that a high current out of range flew
through a measured target, an error on the measured target is monitored
easily.
When digital output values exceed the set peak current detection value
consecutively for the duration of the peak current detection time set in
advance, an error can be detected.
When an input current is around 0A, a CT's conversion accuracy is low. To
avoid digital output of such an unstable CT input value, digital output values
within the set value can be dropped to 0 forcibly.
A digital output value can be scaled into a value within the range of the set
scaling upper limit value to lower limit value.
The sequence programming for scale conversion can be omitted.
When a digital output value enters the alert output range set in advance, an
alert is output.
When a change rate of a digital output value is equal to or more than the
rate alarm upper limit value (%/s) or that is equal to or less than the rate
alarm lower limit value (%/s), an alert is output.
The maximum and minimum of digital output values or scaling values are
stored to the buffer memory for each channel.
A digital output value or scaling value can be logged. 5000 data can be
logged for each channel.
CHAPTER 3 SPECIFICATIONS
Reference
Page 34,
Section 4.2
Page 35,
Section 4.3
Page 35,
Section 4.4
Page 36,
Section 4.5.1 (1)
Page 37,
Section 4.5.1 (2)
(a)
Page 37,
Section 4.5.1 (2)
(b)
Page 38,
Section 4.5.1 (2)
(c)
Page 39,
Section 4.5.1 (3)
Page 42,
Section 4.6
Page 44,
Section 4.7
Page 47,
Section 4.8
Page 48,
Section 4.9
Page 51,
Section 4.10 (1)
Page 53,
Section 4.10 (2)
Page 57,
Section 4.11
Page 58,
Section 4.12
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