111
Analog Input Units
Section 5-1
4 to 20 mA
The 4- to 20-mA range corresponds to the hexadecimal values 0000 to 1770
(0 to 6000). The entire data range is FED4 to 189C (–300 to 6300). If the input
current falls below 3.2 mA, the open-circuit detection function will activate and
the converted data will be set to 7FFF.
Number of Inputs
The number of inputs can be limited to four by turning ON pin 14 of the DIP
switch. Changing the number of inputs from eight to four reduces the sam-
pling time from 8 ms to 4 ms, providing faster conversion.
If four inputs are used, the number of words allocated to the Input Unit in the
PC is also reduced to 4 words. When only four inputs are used, inputs 0, 2, 4
and 6 are used (i.e., inputs 1, 3, 5 and 7 cannot be used.)
Averaging Function
Setting
The averaging function can be enabled for all inputs (0 through 7) by turning
ON pin 13 of the DIP switch. The averaging function outputs the average (a
moving average) of the last eight input values as the converted value. Use this
function to smooth inputs that vary like the one in the following diagram.
Note The time required for refreshing converted data remains 1 ms/point when the
averaging function is enabled. The first communications data after the power
is turned ON will be output after averaging eight samples.
Open-circuit Detection
Function
The open-circuit detection function is activated when the input range is set to
1 to 5 V and the voltage drops below 0.8 V, or when the input range is set to 4
189C (6300)
1770 (6000)
−
1 mA
0 mA
20 mA 21 mA
FED4 (
−
300)
0000 (0)
Converted data
Hexadecimal (Decimal)
Current
189C (6300)
1770 (6000)
7FFF
0000 (0)
FED4 (
−
300)
3.2 mA
4 mA
20 mA 20.8 mA
Converted data
Hexadecimal (Decimal)
Current
Time
Actual input
Input after averaging
Summary of Contents for DRT1-COM
Page 1: ...OPERATION MANUAL Cat No W348 E1 05 DRT1 COM GT1 Series DeviceNet MULTIPLE I O TERMINAL ...
Page 2: ...DRT1 COM GT1 Series DeviceNet MULTIPLE I O TERMINAL Operation Manual Revised May 2003 ...
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Page 233: ...DRT1 COM GT1 Series DeviceNet MULTIPLE I O TERMINAL Cat No W348 E1 05 OPERATION MANUAL ...