DL205 Analog Manual, 7th Edition Rev. D
5-9
Chapter 5: F2-08AD-2, 8-Ch. Analog Voltage Input
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Module Operation
Channel Scanning Sequence for a DL230 CPU (Multiplexing)
Before beginning to write the control program, it is important to take a few minutes to
understand how the module processes and represents the analog signals.
Depending on the type of CPU being used, the F2-08AD-2 module can supply different
amounts of data per scan. The DL230 can obtain one channel of data per CPU scan. Since
there are eight channels, it can take up to eight scans to get data for all channels. Once all
channels have been scanned the process starts over with channel 1. Unused channels are not
processed, so if only two channels are selected, each channel will be updated every other scan.
The multiplexing method can also be used for the DL240/250-1 and DL260 CPUs.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
b
C
D
Channel 1
Scan N
Read the data
Store data
Read Inputs
Execute Application Program
Channel 2
Scan N+1
Channel 7
Scan N+6
Channel 8
Scan N+7
Channel 1
Scan N+8
Scan
Write to Outputs
System With
DL230 CPU
(repeat for ch. 3--6)
Summary of Contents for DL205
Page 1: ...DL205 Analog I O Manual Manual Number D2 ANLG M ...
Page 2: ...Notes ...
Page 6: ...Notes ...