DL205 Analog Manual, 7th Edition Rev. D
7-11
Chapter 7: F2-04THM, 4-Channel Thermocouple Input
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B
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D
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 F2-04THM 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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b
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D
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 ...
