Read Variable Area Command - Omron K7GE-MG User Manual

6-9-2

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
Example:
Assume that the measurement value and status is read from the slave with unit number 10.
The variable area addresses for the measurement value and status are H'0001 to H'0013.
Insulation Resistance Monitoring Device User's Manual (N224)
Read start address Number of elements
2 2
CRC-16 calculation range
This number specifies the transmission's destination. Specify the unit number of the
K7GE-MG Main Unit.
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 6-3 Variable Area Map on page 6-5.
Specify the number of variables to read. You can specify up to 46 variables
(H'002E).
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 the received function code. However, 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'03 Variable data error
H'04 Operation error
CRC-16
2 bytes
CRC-16
2 bytes
Error name
The command ended normally.
The number of elements exceeds the
allowed range.
A system error occurred.
6 Remote Monitoring
Description
6 - 25
6