Omron EJ1G, User Manual

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134
Detailed Description of Services
Section 6-4
6-4-3 Composite Read from Variable Area
This service reads in order the contents of specified addresses in a variable
area.
■
Command
Service Request PDU
■
Response
Service Response PDU
The read data is read together with the variable type, in the order specified in
the command.
1. Variable Type and Read Address
Refer to Parameter List on page 175.
Composite reads cannot be performed for the DA/9A variable types.
2. Bit Position
The EJ1G does not support bit access. Fixed to 00.
3. Response Codes
4. No. of Read Data Items (Variable Type + Read Data)
MRC
2 2
0 1
4
SRC
2
0 4
2
0 0
2 4 2
0 0
Variable
type
Read address Bit
position
Variable
type
Read address Bit
position
Response code Error name Cause
1002 Command too short The command is not long enough.
1101 Area type error The corresponding variable type does not
exist.
110B Response too long The number of elements exceeds the
maximum.
1100 Parameter error Bit position is not 00.
7011 Operation error (7011) The command cannot be executed due to
a device error.
0000 Normal completion Processing was completed normally.
Read data length No. of read data items
For double-word (8-digit) variable type 32 max. (0020H)
For word (4-digit) variable type 41 max. (0029H)
MRC
2
0 1
4
SRC
2
0 4
2
2
Response
code Variable
type
Read data
Read data
Variable
type
No. of elements
×
8 or 4
No. of elements
×
8 or 4