Read Variable Area Command - Omron K7DD User Manual

7 Communications
7-6-2

Read Variable Area Command

 Command Frame:
Slave Function
address code
H'03
1 1
Slave address
Function code
Read start address
Number of elements
CRC-16
 Response Frame:
Slave Function
address code
H'03
1 1
Slave address
Function code
Byte count
Read data
CRC-16
 Response Codes:
Function code
H'03
H'83
7 - 12
Read start address Number of elements
2 2
CRC-16 calculation range
A number used to identify a destination device. Specify the unit number of the
K7DD.
The unit number can be set between H'01 to H'63 hexadecimal (01 to 99 decimal).
The Read Variable Area Command's function code is H'03.
Specify the address of the variable area to start reading in 2-byte hexadecimal.
Refer to 7-7 Variable Area Map (P.7-17).
Specify the number of variables to read. You can specify up to 125 variables
(H'007D).
This check code is calculated with the data from the slave address to the end of the
data.
Byte
Read data (for number of elements)
count
1
CRC-16 calculation range
The number specified in the command frame is entered as-is.
This is a received function code. H'80 is added if an error occurs.
Contains the number of bytes of read data. The byte count is a hexadecimal.
Contains the read data value.
This check code is calculated with the data from the slave address to the end of the
data.
Error code
--- Normal end
H'02 Variable address error
H'03 Variable data error
H'04 Operation error
CRC-16
2 bytes
CRC-16
2 bytes
Error name
The command ended normally.
The variable address was accessed in
excess of H'FFFF.
The number of elements exceeds the
allowed range.
No response can be made in this system
state.
Power Line Data Generator User's Manual (N233)
Description