
6. CONNECTION OF I/O UNITS TO
MACHINE INTERFACE
B–63783EN/01
88
NOTE
This analog input module has four input channels, but its
digital output section uses one 12–bit output in the 3 bytes
for the number of occupied input points. That is, the ladder
dynamically selects which channel to use. A channel
switching DO for channel selection is in the 2 bytes for the
number of occupied output points.
(About digital output)
This analog input module has four input channels, but its digital output
section uses one 12–bit output in the 3 bytes for the number of occupied
input points. The format of the output is as listed below.
7
D07
Module internal address
Xm (even address)
Xm+1 (odd address)
0
6
D06
0
5
D05
CHB
4
D04
CHA
3
D03
D11
2
D02
D10
1
D01
D09
0
D00
D08
D00 to D11 form 12–bit digital output data. D00 and D11 correspond to
weights of 2
0
and 2
11
, respectively.
D11 corresponds also to the sign bit of a twos complement representation.
CHA and CHB represent analog input channels. That is, if the 2 bytes
mentioned above are read by the PMC program, D11 to D00 reflect the
A–D conversion result for input channels represented by CHA and CHB.
See the following description about channel selection for details of CHA
and CHB. There are some items to be considered when data is read from
the PMC program. See the relevant description on assignment in Section
6.3.
(About channel selection)
For this analog input module, you must use the PMC program to select
from the four channels a channel to be used for output to the digital output
section. CHA and CHB in the 2 bytes for the number of occupied output
points are used as DO points for channel selection. They are mapped as
shown below.
6.3.14
Analog Input
Specification