Omron E5CN-H Communications Manual

Modbus
SECTION 5 Modbus Communications Procedure
5-10
Response Frame
Response Code
◆ Reading Undisplayed Parameters
It is possible to read the parameters that are not displayed due to
display settings as well as the parameters that are never displayed in
the Controller.
Example Command and Response
The following example shows the command and response when
reading the process value (slave address: H'01).
Process Value in Four-byte Mode
• Address: H’0000; Read data: H’000003E8 (100.0 °C)
Name Description
Slave address The value from the command frame is entered as-is.
Function code This is the received function code.
When the function ended normally, the function code is left as-is. When an
error occurred, the hexadecimal value of H’80 is added to the function code
to indicate that the response is an error response.
Example: Received function code = H’03
Function code in response frame when an error occurred = H’83
Byte count Contains the number of bytes of read data.
Number of elements Contains the number of setting data items that were read.
CRC-16 This check code is calculated with the data from the slave address to the
end of the data.
For details on the CRC-16 calculation, see CRC-16 Calculation Example in
5.1 Data Format on page 5-3.
Slave
address
Function
code
Byte
count
111 2
CRC-16
0 to 212 (2 × 106)
Read data (for the
number of elements)
H'03
Function
code
Error
code
Error name Cause
H'83 H'02 Variable address error The read start variable address is incorrect.
• The variable area number is incorrect.
H'03 Variable data error The number of elements exceeds the
allowed range.
H'03 --- Normal completion No errors were found.
Command:
Response:
01
01 03
03
04
00 00 00 02
00 00 03
E8
FA 8D(CRC-16)
C4 0B(CRC-16)

Omron E5CN-H Specifications

General

Brand	Omron
Model	E5CN-H
Category	Controller
Language	English