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
0
1
2
3
4
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.
