110
Details of Services Section 7-3
(3) Number of Elements
Note (1) If the Read Start Address is outside of the variable area, the returned
read data will all be 0, but the specified number of elements will be re-
turned and the processing will end in “normal completion.”
(2) If the Read Start Address is within the variable area and the Read End
Address (Read Start Address + Number of Elements) is beyond the last
variable area address, the read operation will be performed as long as the
amount of data up to the last variable area address is within the specified
range of the number of elements. The read data beyond the end of the
variable area will all be set to 0. (See the following example.)
Reading Two Elements and Exceeding the Last Variable Area Address
In this case, the second element does not exist, so the read data will be
AAAA0000.
■ Response Codes
Write Variable Area This service writes data to a variable area.
■ Service Request PDU
Number of
elements
Processing
0000 The read operation is not performed (read data is not
appended to the service response PDU), and processing ends
in “normal completion.”
0001 to 000A The read operation is performed, and processing ends in “nor-
mal completion” (hexadecimal display).
AAAA
Read Start Address →
Read End Address →
← Last addres
Address Variable area
* * * *
* * * *
* * * *
Response
code
Error name Cause Error
priority
1001 Command too long The command is too long. 1
1002 Command too short The command is too short. 2
1101 Area type error The variable type is incorrect. 3
110B Response too long The number of elements is larger
than “000A.”
4
1100 Parameter error The bit position is not “00.” 5
0000 Normal completion No error None
MRC SRC
0 1 0 2 00
2 2 2 4 2 4
Variable
Type
Write Start
Address
Bit
Position
Number of
Elements
Write Data
0 to 40
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