Omron DRT2 SERIES DEVICENET SLAVES - OPERATION MANUAL 04-2008 Operation Manual page 345

Analog Input Terminals
AD Conversion Data
Conversion Speed
DRT2-AD04
DRT2-AD04H
324
■ Input Range: 4 to 20 mA
The current range 0 to 20 mA corresponds to 0000 to 7530 hex (0 to 30,000).
The convertible data range is FA24 to 7B0C hex (
The current range 3.2 to 4 mA corresponds to FA24 to 0000 hex (
If the input current is below the input range (input current less than 3.04 mA),
a disconnection is detected and the data is set to 7FFF hex.
Conversion data
Hexadecimal (decimal)
7B0C (31500)
7530 (30000)
7FFF
0000 (0)
FA24 (−1500)
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. When pin 7 of the DIP Switch is turned ON,
the AD conversion data will be expressed in signed binary.
15 14 13
Word +0
Word +1
Word +2
Word +3
The AD conversion data for 4 input points is refreshed every 3.82 s max.,
although the conversion speed will vary depending on the functions and num-
ber of AD conversion points being used. Refer to 7-4-4 Calculating the Con-
version Cycle (DRT2-AD04 Only) for details.
The AD conversion data is refreshed every 250 ms. After a step response is
input, however, it may take up to 650 ms until 90% of the input value is
reached and the AD conversion data can be transferred.
4 mA
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 7-4
1,500 to 31,500).
–
1,500 to 0).
–
Clamped above
20.8 mA.
Current
20 mA 20.8 mA
4 3 2 1 0