USB & RS232 Communication
Data Link Layer
EPOS4 Communication Guide
CCMC | 2019-11 | rel8759
2-19
12) Calculate the CRC (use algorithm as to
chapter “2.2.3.2 CRC Algorithm” on page 2-14).
Thereby, valid value for CRC is “0” (zero):
ArrayLength= Len + 2
CrcValue = CalcFieldCRC(&DataArray, ArrayLength)
Valid = (0x0000 == CrcValue)
G) CHECK
13) Check the EPOS4 receive frame.
Important:
• If the error code is unequal to “0” (zero), the command was not processed!
• Check
chapter “6 Communication Error Code Definition” on page 6-47 for error details.
• Fix the error before attempting to resend the data frame.
Response frame
OpCode
BYTE
Read object
0x00
Len
BYTE
Number of words
0x04
Parameters
BYTE
Node-ID
0x01
DWORD
Communication error
0x00000000
no error
DWORD
Data bytes read
0x00009001
36’865 inc