Toshiba Tosvert RS485 - Manual (Page 4)

E6581315
3
1. General outlines of the communication function
This manual explains the RS485 communication function provided for the TOSVERT VF-AS1 series
of industrial inverters.
(1) RS485 communication by the use of a two-wire RS485 communication port (standard function)
(2) RS485 communication by the use of a four-wire RS485 communication port (standard function)
By using these communication functions in combination with the computer link function designed to
establish a link between a higher level computing machine or controller (hereinafter referred to as a
computer) and each inverter on the network, or with the inter-drive communication function that al-
lows proportional control of inverters without using a computer, you can set up a network for data
communication between inverters.
There are two communication protocols available: Toshiba Inverter Protocol and MODBUS-RTU
Protocol (this command does not support all commands). To select a protocol, the communication
protocol selection parameter f807 or f829 is used. (Refer to Section 3. Communication proto-
col.)
<Computer link>
By preparing the program (explained later), the following information can be exchanged between the
computer (host) and the inverter.
(1) Monitoring function (used to monitor the operating status of the inverter: Output frequency,
current, voltage, etc.)
(2) Command function (used to issue run, stop and other commands to the inverter)
(3) Parameter function (used to set parameters and read their settings)
<Inter-drive communication function>
Master inverter sends the data, that is selected by the parameter, to all the slave inverters on the
same network. This function allows a network construction in which a simple synchronous or
proportional operation is possible among plural inverters (without the host computer).
As for data communication codes, the TOSVERT VF-AS1 series of inverters support the binary
(HEX) code, in addition to the JIS (ASCII) code. A communication number is used to access the de-
sired data item.
* The smallest unit of information that computers handle is called a “bit (binary digit),” which repre-
sents the two numbers in the binary system: 1 or 0. A group of 16 bits is referred to as a “word,”
which is the basic unit of information the VF-AS1 series of inverters use for data communication.
One word can handle data items of 0 to FFFFH in hexadecimal notation (or 0 to 65535 in decimal
notation).
BIT15 BIT8BIT7 BIT0
1 bit
1 word
(1) 2-wire RS485 communication
connector
(2) 4wire RS485 communication
connector