Toshiba RS-485 operation manual Overview, Communication specifications

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1. Overview

By using RS-485 Option Unit, a network can be constructed that allows communication between a host computer and multiple ASD units. A maximum of 32 Option Units can be connected on the same network. And two ASDs can be connected to one Option Unit. A maximum of 64 ASDs can be connected on the same network. (If ASD has a CPU whose version is V104 or V103, a maximum of 32 ASDs can be connected on the same network.)

2. Communication specifications

Item	Specifications
Interface	Conforming to EIA RS485 standard
Configuration	4-wire, bus type (terminating resistor is necessary at
	each end of system)
Communication Distance	1,000m maximum
Connection Points	32 units maximum
Number of ASDs per one Option Unit	2 units maximum
Number of ASDs on the Same Network	64 units maximum (If ASD has a CPU whose version
	is V104 or V103, a maximum of 32 ASDs can be
	connected on the same network.)
Communication Line Isolation	Not isolated
Synchronization Method	Start-stop synchronization
Error Detection Method	Parity, checksum
Communication Speed	1200/2400/4800/9600 baud selectable (parameter
	and switch selection)
Data Code	ASCII code, binary code
Other	Time-out function available

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