Energy Meter Manual

8-2
<Toc> <Ind> <8. PR201 Original Communication Protocol>
IM 77C01E01-10E
8.3 Command/Response Format
Command components:
STX Command Parameter
Station
number
Data Checksum ETX CR
Checksum range
1 byte 2 bytes 1 byte 2 bytes
Variable-
length
2 bytes 1 byte 1 byte
STX: Start of Text (hexadecimal: 02)
Command: 2-byte ASCII code (DG or DP)
Parameter: 1-byte ASCII code (0 to Z)
Station number: 2-byte ASCII code (01 to 63)
Data: No data is found at data read-out time. When a setting value is
changed, a variable-length ASCII code is set (size in byte varies
depending on the parameter).
Checksum: 2-byte ASCII code (00 to FF)
This value is obtained by adding the data (hex.) in a checksum range
and converting the lower 2 digits of the resulting value.
ETX: End of Text (hexadecimal: 03)
CR: Carriage Return (hexadecimal: 0D)
Response components:
1 byte 2 bytes 1 byte 2 bytes
Variable-
length
2 bytes 1 byte 1 byte
STX Response Parameter
Station
number
Data Checksum ETX CR
Checksum range
STX: Start of Text (hexadecimal: 02)
Response: 2-byte ASCII code (DG or DP)
Parameter: 1-byte ASCII code (0 to Z)
Station number: 2-byte ASCII code (01 to 63)
Data: Variable-length ASCII code (byte size depends on the type of param-
eter)
Checksum: 2-byte ASCII code (00 to FF)
ETX: End of Text (hexadecimal: 03)
CR: Carriage Return (hexadecimal: 0D)
NOTE
When a communication error occurs, the parameter Z of the DG command must be trans-
mitted to read out an error response. The details of the communication error can be deter-
mined by the contents of the error response.