Maxsine EP3 AC Series, Руководство пользователя

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Chapter 6 Communication functions
192
For example, read the section 0 No. 05 parameter of station number 01H servo drive.
STX ‘:’
ADR
‘0’
‘1’
CMD
‘0’
‘3’
Initial data
position
‘0’
‘0’
‘0’
‘5’
Data
number
‘0’
‘0’
‘0’
‘2’
LRC Check
‘F’
‘5’
End1 ‘0DH’(CR)
End0 ‘0AH’(LF)
LRC calculate process is as follows:
01H+03H+00H+05H+00H+02H=0BH ，
Taking two's complement of OBH is F5H. so LRC is ‘F’, ‘5’.
PTU mode:
PTU mode adopts CRC (Cyclical Redundancy Check) frame check. The following steps
are explaining CRC frame check calculation:
Step 1: Initialize one 16 bits register with content of FFFFH which is called CRC
register.
Step 2: Work the first byte of command information and the low byte of 16-bits CRC
register, and store the result back to CRC register.
Step 3: Check the lowest bit (LSB) of CRC register. If this bit is 0, then move right for
one bit; if this bit is one, the CRC register value moves right for one bit and
then work the XOR (exclusive or operation) with A001H.
Step 4: Go back to step 3 until the step 3 has been executed for eight times, then go to
step 5.
Step 5: Repeats step 2 to step 4 for the next byte of command information, until all the
types have completed the above processing. And the content of CRC register
is CRC frame check.
Explanation: after working out the CRC frame check, in the command information, it needs
to fill the CRC low bit firstly and then fill the CRC high bit. Please refer to the following