DL205 Analog Manual, 7th Edition Rev. D
6-9
Chapter 6: F2-04RTD 4-Channel RTD Input
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Module Operation
Before beginning to write the control program, it is important to take a few minutes to
understand how the module processes the analog signals.
Channel Scanning Sequence for a DL230 CPU (Multiplexing)
The F2-04RTD module can supply different amounts of data per scan, depending on the type
of CPU being used. The DL230 can obtain one channel of data per CPU scan. Since there are
four channels, it can take up to four 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 DL240/250-1/260 CPUs.
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Channel 1
Scan N
Read the data
Store data
Read Inputs
Execute Application Program
Channel 2
Scan N+1
Channel 3
Scan N+2
Channel 4
Scan N+3
Channel 1
Scan N+4
Scan
Write to Outputs
System With
DL230 CPU
Summary of Contents for DL205
Page 1: ...DL205 Analog I O Manual Manual Number D2 ANLG M ...
Page 2: ...Notes ...
Page 6: ...Notes ...
