Detailed Description Of Services; Multiple Read From Variable Area - Omron EJ1 User Manual

Detailed Description of Services

7-5

Detailed Description of Services

7-5-1

Multiple Read from Variable Area

Command
Response
196
This service reads data from the variable area.
Function
code
Slave Read start
address
address
H'03
1 1 2
Function
code
Slave
Byte
Read data 1
address
count
H'03
1 1 Number of
1
elements
1. Read Start Address
Refer to Parameter List on page 233.
2. No. of Elements
Specify the number of elements to read. The specification range is from
H'0001 to H'0050 (1 to 80 elements).
3. Byte Count
The number of bytes of data that was read is returned.
4. Response Codes
Function Error Error name
code code
H'83 H'01 Function code error
H'02 Variable address error The read start address is not correct.
H'03 Variable data error
H'03 --- Normal end
Command/Response Example
The following command reads the process value of channel 1.
Slave address: H'01
Read start address: H'0200
Read data: H'03E8 (when the process value is 100.0 C)
Command: 01 03 0200 0001 85B2 (CRC-16)
Response: 01 03 02 03E8 B8FA (CRC-16)
No. of
CRC-16
elements
2 2
Read data n
2 bytes
A function code that is not supported was
specified.
• The command is too long.
• The command is not long enough.
• The number of elements has exceeded
the maximum limit.
The service was processed normally.
Section 7-5
CRC-16
2
Cause