Delta Electronics ASDA-B Series manual STX Communication Start, ADR Communication Address

Chapter 8 MODBUS CommunicationsASDA-B Series

STX (Communication Start)

ASCII Mode: ’:’ character

RTU Mode: A silent interval of more than 10ms

ADR (Communication Address)

The valid communication addresses are in the range of 1 to 254.

For example, communication to AC servo drive with address 16 decimal:

ASCII Mode: ADR=’1’,’0’ => ‘1’=31H，’0’=30H

RTU Mode: ADR = 10H

CMD (Command Codes) and DATA (Data Characters)

The format of data characters depends on the command code. The available command codes and examples for AC servo drive are described as follows:

Command code: 03H, read N words. The maximum value of N is 10.

For example, reading continuous 2 words from starting address 0200H of AC servo drive with address 01H.

ASCII Mode:

Command message: Response message:

STX	‘:’
ADR	‘0’
	‘1’
CMD	‘0’
	‘3’
	‘0’
Starting data	‘2’
address	‘0’
	‘0’
	‘0’
Number of data	‘0’
	‘0’
	‘2’
LRC Check	‘F’
	‘8’
End 1	(0DH)(CR)
End 0	(0AH)(LF)

STX

ADR

CMD

Number of data (Count by byte)

Contents of starting

data address

0200H

Contents of second

data address

0201H

LRC Check

End 1

End 0

‘:’

‘0’

‘1’

‘0’

‘3’

‘0’

‘4'

‘0’

‘0’

‘B’

‘1’

‘1’

‘F’

‘4’

‘0’

‘E’

‘8’

(0DH)(CR)

(0AH)(LF)

8-10 Revision January 2009