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IM 34M06P15-03E 2nd Edition: Jan. 31, 2012-00
PDU Configuration
This subsection describes the configuration of function codes and data.
z Specifying Device Numbers in PDU
"(Device number) - 1" is specified in the PDU for setting a device number.
The above does not apply to file and record numbers specified at Read/Write File
Record command.
F020401.VSD
Example: If the status of holding register no. 32 is single-word read at Read Holding
Registers ($03).
Function Code
Data
$03
Starting Holding Register No.
$001F
Read Points
$0001
31 ($001F) is specified as the starting
address of the holding register for reading
holding register no.32.
Figure 2.4.1 Specifying Device Numbers
Device numbers stored in responses are request command device numbers.
Tip
$0000 is used in the PDU for specifying the starting coil number 00001 corresponding to I0001.
z How to Read the Format
This subsection explains how to read the request/response format block diagram.
F020402.VSD
Function Code
Data
$01
1-byte 2-byte 2-byte
Starting Coil Nos.
($0000 to $FFFF)
Read Points
($0001 to $07D0)
Area Name
Frame Contents
Settings/Storage
Range
Area Size
Figure 2.4.2 How to Read Format
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