316
Analog Input Terminals
Section 5-7
points, 2 ms/2 points, or 1 ms/1 point, making conversions faster. In accor-
dance with the number of inputs, the number of words allocated to the Analog
Input Terminal in the PLC for the Master Unit will also be set to 4 words/4
points, 3 words/3 points, 2 words/2 points, or 1 word/1 point. When the num-
ber of inputs is 3, Inputs 0, 1, and 2 will be used; when the number of inputs is
2, Inputs 0 and 2 will be used; and when the number of inputs is 1, Input 0 will
be used.
Averaging Function (8-
time Moving Average)
When pin 7 of DIP switch SW102 is ON, the averaging function (8-time mov-
ing average) will be activated for all Inputs 0 to 3.
The averaging function outputs the average of the previous 8 inputs (moving
average) as conversion data.
Turn ON this pin when the inputs fluctuate slightly but frequently as shown in
the following figure. The averaging function will make the actual inputs
smoother.
Note
Even in this case, conversion data will be updated at the normal rate of 1 ms/
point. After power is turned ON, the data transmitted first are sampled 8 times,
averaged, and then output.
Burnout Detection
Function
When the input range is 1 to 5 V or 4 to 20 mA, and the input signal is less
than 0.8 V or less than 3.2 mA, the input line is deemed to be disconnected,
and the burnout detection function is activated. Once the burnout detection
function is activated, the conversion data is set to 7FFF Hex.
The time required to activate or cancel the burnout detection function is the
same as the time required for conversion.
If input returns to the convertible range, the burnout detection function will be
cancelled automatically, and normal data conversion will be resumed.
Precautions on Using Shared Power Supply for Input Devices
If the power supply is shared by input devices, and a disconnection occurs
during voltage input, the status of the circuit becomes as shown in the follow-
Actual input
Averaged input
Time
