（
2
）
networking methods with VFD as slave:
Fig9-2 The networking of multi-machine interaction
Host
VFD
RS485
Slave
VFD
Slave
VFD
Slave
VFD
Slave
VFD
8.2.2 Communication protocol
The VFD can either used as a host or slave in RS485 network. It can be used for
controlling our other VFDs as host to achieve multi-level linkage, or controlled
by host (PC or PLC) as a slave. The specific communication mode as follows:
VFD is used as slave, in point-to-point communication of master-slave mode.
Host sends commands from broadcast address, while slave doesn’t answer;
VFD is used as host, sending commands from broadcast address, while
slave doesn’t answe;
The address, baud rate and data format of the VFD can be setup by using the
keyboard or the serial communication;
message of error is reported by slave, in the recent response frame against
host polling.
Ø
Ø
Ø
Ø
8.2.3 Communication Interface
The communication is using RS485 interface, with asynchronous serial and
half-duplex transmission. The default communication protocol is in ASCII mode.
The default data format: 1 start bit, 7 data bits, 2 stop bits.
The default rate is 9600bps. Communication parameter settings reference
P3.09 ~ P3.12 function code.
8.3
The ASCII Communication Protocol
Character structure:
10 characters box
（
For ASCII
）
(
1-7-2 format, no parity)
Start
bit
BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7
Stop
bit
Stop
bit
Larson Electronics, LLC
Phone:
Fax: (903) 498-3364
www.larsonelectronics.com
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VFD-1P-220.240-1HP-7A-DCM
(877) 348-9680