Omron PRT1-COM Operation Manual page 127

Analog Input Units
Number of Inputs
1 to 5 V
The 1- to 5-V 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 voltage
falls below 0.8 V, the open-circuit detection function will activate and the
converted data will be set to 7FFF.
Converted data
Hexadecimal (Decimal)
189C (6300)
1770 (6000)
7FFF
0.8 V
0000 (0)
FED4 (--300)
1 V
0 to 20 mA
The 0- 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). A negative
voltage is expressed as a two's complement (16 bits). If the line is disconnected,
the data will be the same as an input of 0 mA (0000 Hex).
Converted data
Hexadecimal (Decimal)
189C (6300)
1770 (6000)
0000 (0)
--1 mA
0 mA
FED4 (--300)
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.
Converted data
Hexadecimal (Decimal)
189C (6300)
1770 (6000)
7FFF
3.2 mA
0000 (0)
4 mA
FED4 (--300)
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 sampling
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.)
Section 7-1
Voltage
5 V 5.2 V
Current
20 mA 21 mA
Current
20 mA 20.8 mA
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