DL205 Analog Manual, 7th Edition Rev. D
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Chapter 11: F2-08DA-2, 8-Channel Analog Voltage Output
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Writing Values: Pointer Method and Multiplexing
Two methods are used to read data values in the DL205, pointer and multiplexing. When to
use either method and how to use it will be discussed here. Since the pointer method will not
work if the PLC has a DL230 installed, only the multiplexing method can be used. Either
method for reading the data values can be used with the DL240, DL250-1 and DL260 CPUs,
however, the pointer method will simplify programming the PLC.
Writing Values (Pointer Method) for the DL240, DL250-1 and DL260 CPUs
Once the data values have been calculated they must be entered into the program in order to
output the values. The DL205 series has special V-memory locations assigned to each base slot
that will greatly simplify the programming requirements. With these V-memory locations, the
number of channels to update are specified, also, where to read the data that is written to the
output is specified.
NOTE:
DL240 CPUs with firmware release version 3.0 or later and. DL250 CPUs with firmware release version 1.33 or
later support this method.
The following example program shows how to setup these locations. Place this rung anywhere
in the ladder program, or in the initial stage if stage programming instructions are being used.
This is all that is required to write the data to V-memory locations. Once the data has been
written to V-memory math can be used on the data, compare the data against preset values, etc.
V2000 is used in the example but any user V-memory location can be used. In this example the
module is installed in slot 3. Be sure to use the V-memory locations for the module placement.
The pointer method automatically converts values to BCD.
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SP0
LD
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LDA
O2000
OUT
V7703
This loads an octal value for the first V-memory location that will be
used to store the output data. For example, the O2000 entered here
would designate the following addresses:
Ch1 -- V2000, Ch 2 -- V2001.....Ch8 -- V2007
OUT
V7663
Special V-memory location assigned to slot 3 that contains the
number of channels to scan.
LD
Loads a constant that specifies the number of channels to scan and
the data format. The lower byte, most significant nibble (MSN)
selects the data format (0=BCD, 8=Binary), the LSN selects the
number of channels (1--8).
- or -
The binary format is used for displaying data on some operator
interfaces. The DL230/240 CPUs do not support binary math
functions, whereas the DL250 does.
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K
88
The octal address (O2000) is stored here. V7703 is assigned to slot
3 and acts as a pointer, which means the CPU will use the octal
value in this location to determine exactly where to store the output
data.
Summary of Contents for DL205
Page 1: ...DL205 Analog I O Manual Manual Number D2 ANLG M ...
Page 2: ...Notes ...
Page 6: ...Notes ...
