Omron CRT1 - 10-2008 Operation Manual page 326

Analog Input Slave Units
AD Conversion Data
Conversion Speed
■ Input Range: 4 to 20 mA
The current range 4 to 20 mA corresponds to 0000 to 1770 hex (0 to 6,000).
The convertible data range is FED4 to 189C hex (
current is below the input range (input current less than 3.04 mA), a discon-
nection is detected and the data is set to 7FFF hex.
Conversion data
Hexadecimal (decimal)
189C (6300)
1770 (6000)
7FFF
0000 (0)
4 mA
FED4 (−300)
3.2 mA
3.04 mA
(Disconnection detected below 3.04 mA.)
Negative AD conversion data is expressed as two's complements. The NEG
instruction (two's complement conversion) can be used to obtain the absolute
value of the two's complement.
Bit 15 14 13
First word + 0
First word + 1
First word + 2
First word + 3
The AD conversion data for 4 input points is refreshed every 3.82 ms max.,
although the conversion speed will vary depending on the functions and num-
ber of AD conversion points being used. Refer to 6-4-3 Calculating the Con-
version Cycle for details.
12 11 10 9 8 7 6 5
Input 0 AD conversion data
Input 1 AD conversion data
Input 2 AD conversion data
Input 3 AD conversion data
Section 6-4
300 to 6,300). If the input
–
Clamped above
20.8 mA.
Current
20 mA 20.8 mA
4 3 2 1 0
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