SMC Networks HRS012-A Operation Manual page 67

NO Item
Start text
1 STX(02h) The code to specify the head of the message. Added to the head of the characters to
be sent.
End text
2 ETX(03h) The code to specify the end of the message. Added to the end of the characters to be
sent. Other than BCC.
Slave Slave address which is set to each product. Can be changed by setting.
3
Address The address to identify the device.
4 Request Request identifier. R (reading) or W (writing)
5 Command Command to reading or writing.
Writing To request writing, write the data in this area to the object data.
6
Reading To request reading, set the object data in this area.
EXOR algorithm of all characters from STX to ETX is read with the check code for
error detection.
7 BCC
This code (BCC) is not included in "response" if BCC check is not selected when
setting the communication.
Acknowledge code.
8 ACK(06h) This is included in the response from the product when there is no error in the
received request.
Negative acknowledge code.
9 NAK(15h) This is included in the response from the product when there is an error in the
received request.
Error content is included in the response when there is an error in the received
request. Refer to the table below for exception codes.
Exception
10
code
∗1：Exception code "0" is included in the response regardless of the presence of the
∗2：The exception with the highest number is included in the response when two or
HRS Series
Table 5.5-1 Format data
Exception
Exception
code
Equipment malfunction
0
Memory error
Out of set range
1 Value data is out of "set range specified independently by set
parameter"
Setting not allowed.
Changing of requested communication parameter is prohibited. Or
communication parameter to read does not exist.
2
Writing of the communication mode is requested while the
communication mode change is set to RO (read only)
Writing to PV (measured value) is requested.
Abnormal code
ASCII code other than numerical data is requested (specified) to the
3 location for numerical data.
ASCII code other than "0" or"-" is requested (specified) to the
location for symbol.
4 Format error
5 BCC error
6 Overrun error
7 Fleming error
8 Parity error
request error because memory error is present.
more errors have occurred.
Chapter 5 Simple communication protocol function
Explanation
HRX-OM-M091
5.5 Message configuration
5-13