Toshiba RS-485 operation manual Connection and start-up

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4. Connection and start-up

Connect the ASD with a host computer according to the procedure mentioned below.

Procedure

(1)Set the communication speed to SW on the RS-485 Option Unit.

(2)Connect terminating resistor in both ends of units. The RS-485 Option Unit has internal terminating resistor. Set SW3 and SW4 to ON to connect these terminating resistors.

(3)Install the RS-485 Option Unit on a metal panel.

(4)Connect the cable to the removable terminal block. If the stick-lugs are not used, strip the insulation from the wire and insert the wire directly into the terminal. Be sure not to short any wires. Run the cable as shown in the figure. Use a common cable in the system.

(5)Connect the shield of the twisted pair cable to the SHIELD terminal on each RS-485 Option Unit, and make the ground connection. Do not connect Host computer ground to a power ground or any other noise-producing ground connection.

(6)Insert the removable terminal block back into the RS-485 Option Unit.

(7)Connect the communication connectors (INVERTER1 and INVERTER2) of the RS-485 Option Unit to the communication connector (CN1) of the ASD with the optional cable.

(8)Turn on the power of ASD.

(9)Set the communication parameter of the ASD.

Shielded twisted-pair cable

0.2~1.5mm2

(AWG size: 24~16)

HOST

COMPUTER

Terminating TXA resistor

120- 1/2W TXB

RXA

RXB

SG

FG

Ground

(100or less)

RS485

Option Unit

TXA

TXB

RXA

RXB

SG

SHIELD

SW3,SW4 = OFF

RS485

RS485

Option Unit

Option Unit

TXA

TXA

TXB

TXB

RXA

RXA

RXB

RXB

SG

SG

SHIELD

SHIELD

SW3,SW4 = OFF

SW3,SW4 = ON

 

 

Set terminating resistor

6

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Contents RS-485 Option Unit for Tosvert VF-S7 Introduction Carefully read the following notes Prohibited Overview Communication specificationsShield Names and functions of main partsConnection and start-up RXA RXB TXA TXB Shield Dimensions Warranty SpecificationsCommunication parameters
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Manual 8 pages 51.46 Kb

RS-485 specifications

The Toshiba RS-485 is a robust and widely used communication standard designed for industrial applications involving serial data transmission. This technology is particularly appreciated for its ability to connect multiple devices (up to 32 nodes) using a simple twisted pair wiring, making it cost-effective and efficient in environments where reliable communication is essential.

One of the main features of the Toshiba RS-485 is its differential signaling technique. This approach significantly reduces noise and allows for long-distance communication, often exceeding 4000 feet. By utilizing a twisted pair cable, RS-485 devices can communicate at baud rates of up to 10 Mbps, although practical distances may require lower speeds to maintain data integrity.

Toshiba's implementation of RS-485 also supports half-duplex and full-duplex modes, providing versatility in how devices communicate. In half-duplex mode, data can be transmitted in both directions but not simultaneously, making it suitable for applications where control over the communication direction is manageable. Full-duplex mode, on the other hand, enables simultaneous two-way communication, improving the speed and efficiency of data transfer.

The Toshiba RS-485 standard is characterized by its robustness in handling high electromagnetic interference (EMI) and its ability to operate in harsh environments. With a wide operating temperature range, the RS-485 devices can function effectively in various industrial settings, from factories to outdoor applications. Furthermore, the standard supports various voltage levels, providing flexibility in design and functionality.

Another essential technology in the Toshiba RS-485 system is its fault tolerance. The differential signaling allows devices to maintain communication even if one of the wires is compromised, providing greater reliability compared to single-ended systems. Additionally, the use of termination resistors helps mitigate reflections, further enhancing performance.

In summary, Toshiba RS-485 technology provides the backbone for reliable, efficient, and robust serial communication in industrial applications. Its features, including long-distance capabilities, support for multiple devices, resistance to noise, and fault tolerance, make it a preferred choice for many engineers and system designers. This standard not only meets the demands of the industry but also adapts to the evolving technological landscape, ensuring that it remains relevant in the years to come.