Delta Electronics VFD-EL manual RTU mode

Chapter 4 Parameters

	LRC CHK Hi	LRC check sum:
		8-bit check sum consists of 2 ASCII codes
	LRC CHK Lo
	END Hi	End characters:
		END1= CR (0DH), END0= LF(0AH)
	END Lo
RTU mode:
	START	A silent interval of more than 10 ms
	Address	Communication address: 8-bit address
	Function	Command code: 8-bit command
	DATA (n-1)	Contents of data:
	to
		n×8-bit data, n<=40 (20 x 16-bit data)
	DATA 0
	CRC CHK Low	CRC check sum:
	CRC CHK High	16-bit check sum consists of 2 8-bit characters
	END	A silent interval of more than 10 ms

3.2 Address (Communication Address)

Valid communication addresses are in the range of 0 to 254. A communication address equal to 0, means broadcast to all AC drives (AMD). In this case, the AMD will not reply any message to the master device.

00H: broadcast to all AC drives

01H: AC drive of address 01

0FH: AC drive of address 15

10H: AC drive of address 16

:

FEH: AC drive of address 254

For example, communication to AMD with address 16 decimal (10H): ASCII mode: Address=’1’,’0’ => ‘1’=31H, ‘0’=30H

RTU mode: Address=10H

3.3Function (Function code) and DATA (data characters) The format of data characters depends on the function code. 03H: read data from register

06H: write single register

08H: loop detection

The available function codes and examples for VFD-EL are described as follows:

4-88 Revision August 2008, 2ELE, V1.02