6

Communication

There is three control modes: RS-485 communication, AC drive front panel, and external terminals. Only

one mode can be used at a time and is selected by DIP Switch 6 and 7. Programming can only be done

when the AC drive is in stopped mode.

DIP switch settings for control

DIP Switch 6 determines if control is via the AC drives front panel or external terminals. Set DIP switch

6 to OFF for AC drive front panel control and ON for external terminal control

DIP Switch 7 determines if control is local or via RS-485 communication. When DIP Switch 7 is OFF,

the AC drive front panel or external terminals control the drive.

Note: The parameters set via RS-485 communication will remain in memory. Users can still read the status

of the AC drive via RS-485 communication, but cannot send any control commands.

When DIP Switch 7 is ON, the drive is controlled by RS-485 communication. Please verify the AC drive is

fully stopped prior to turn DIP Switch 7 ON. If DIP Switch 7 is turned ON during operation, the error LED

will illuminate.

Computer Controls

Each VFD-L AC Drive has a pre-assigned communication address specified by DIP Switch pins 1 to 6

(Refer to the description of setting up address). VFD-L type Communication agreement: Modbus ASCII

mode, protocol <7, N, 2>, Baud rate 9600. The computer then controls each AC Drive according to its

communication address.

ASCII Modes:

Each 8-bit data is the combination of two ASCII characters. For example, a 1-byte data: 64 Hex, shown as

‘64’ in ASCII, consists of ‘6’ (36Hex) and ‘4’ (34Hex).

Character

‘0’

‘1’

‘2’

‘3’

‘4’

‘5’

‘6’

‘7’

ASCII code

30H

31H

32H

33H

34H

35H

36H

37H

Character

‘8’

‘9’

‘A’

‘B’

‘C’

‘D’

‘E’

‘F’

ASCII code

38H

39H

41H

42H

43H

44H

45H

46H

Data Format

10-bit character frame (For 7-bit character):

(7, N, 2)

Start

bit

01

2

34

5

6

Stop

bit

7-data bits

10-bits character frame

Stop

bit

AC Drive Addresses for RS-485 Communication

VFD-L series communication addresses are 1 to 63, since 0 means broadcast to all AC drives. A DIP

Switch sets to ON for equal to 1 and OFF for equal to 0.

If DIP Switch 7 is OFF during power up, the communication address for the drive is 0008H, this is address

1 (factory default).

If DIP Switch 7 is ON during power up, the address settings are determined by the ON/OFF positions of

DIP Switches 1 to 6. Address 1 is when all switches are set to the OFF position. Switch “1” is the upper bit

and switch 6 is the lower bit.

(A) The addresses will remain in memory when the control mode changes to AC drive panel or external

terminals.