Advantech RS-485 Manual de usuario descargar pdf (Pagina 321)

100

101

ADAM-5000 C-9

Appendix C

The star connection causes a multitude of these discontinuities since

there are several transmission lines and is therefore not recommend.

Note: The recommend method wiring method, that causes

a minimum amount of reflection, is daisy chaining

where all receivers tapped from one transmission line

needs only to be terminated twice.

C.3 RS-485 Data Flow Control

The RS-485 standard uses a single pair of wires to send and receive

data. This line sharing requires some method to control the direction of

the data flow. RTS (Request To Send) and CTS (Clear To Send) are the

most commonly used methods.

Figure C-7 RS-485 data flow control with RTS

Intelligent RS-485 Control

ADAM-4510 and ADAM-4520 are both equipped with an I/O circuit

which can automatically sense the direction of the data flow. No

handshaking with the host (like RTS, Request to Send) is necessary to

receive data and forward it in the correct direction. You can use any

software written for half-duplex RS-232 with an ADAM network

without modification. The RS-485 control is completely transparent to

the user.

1 2 ... 316 317 318 319 320 321 322 323 324 325 326 ... 347 348

Comentarios a estos manuales

Sin comentarios

Advantech RS-485 Manual de usuario Pagina 321

Comentarios a estos manuales

Relacionado con productos y manuales para Digital + i / s analógicas módulos Advantech RS-485