Toshiba VF-A7 instruction manual Using the RS485 port fitted as standard

6.30.2 Using the RS485 port fitted as standard

With the standard serial RS485, you can connect each inverter to a higher-order control system (host computer) to set up a data communications network between inverters. Also, you can establish a data communications link between a computer and each inverter.

Serial RS485 connectors should be used to connect inverters to one another.

■Data transfer specification

Item	Specification
Interface	RS485
Transmission path	Half-duplex transmission [2/4-wire, bus architecture (A terminator needs
specification	to be attached at each end of the system.)]
Transmission distance	Up to 500 m (overall length of the cable)
Number of	Up to 32 units (including a host computer)
connectable units	Up to 32
Synchronization mode	Asynchronous transfer
Data transfer rate	Default setting: 9600 bps (parameter setting)
	Selectable from among1200, 2400, 4800, 9600, 19200 and 38400 bps
Transmission character	ASCII code ... JIS X 0201 8-bit (ASCII)
	Binary code ... Binary code, 8-bit fixed
Stop-bit length	Received by inverter: 1 bit, sent from inverter: 2 bits
Error detecting system	Parity: even/ odd/ non (parameter setting), check sum
Error correction function	Not provided
Response monitoring	Not provided
Transmission code	Sending: 11 bit, Reception: 12 bit(with parity)
Transmission waiting	Possible
time setting
	Action the inverter takes when an timeout occurs: tripping/alarm/no action
Others	→When alarm is selected, "" blinks at the left end of the control panel.
	When tripping is selected, "" is displayed on the control panel.

■An example of the connection of inverters linked to a computer ＜Selective communications＞

When an operation frequency reference is isued by the host computer to the inverter No.

：Wiring

Host computer：Data （Host→Inverter） ：Return data（Inverter→Host）

☆		☆		☆		☆	〜〜	☆
ＩＮＶ		ＩＮＶ		ＩＮＶ		ＩＮＶ		ＩＮＶ		ＩＮＶ
Ｎｏ.００	IG	Ｎｏ.０１	IG	Ｎｏ.０２	IG	Ｎｏ.０３		Ｎｏ.２９	IG	Ｎｏ.３０

IG

(IG)Ignore: Inverters take no action if their numbers do not agree with the number specified in the command( they ignore data received and get ready to receive the next data.)

☆：Use a terminal board, etc., to divide each cable into branches. ①The host computer transmits data to inverters.

②Each inverter receives data from the host computer and checks the number specified by the computer against its number.

③Only the inverter with the number that agrees with that specified by the computer decodes the command and takes action according to it.

④On completion of the action, the inverter returns the results of the action taken to the host computer, with the inverter number added to this information.

⑤In this case, the inverter No. 3 only operates according to the operation frequency command given by the host computer to it across the network.

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