Remote-processing RPC-2350 Manuale Utente Scaricare il pdf (Pagina 20)

CHAPTER 4 SERIAL PORTS

4-1

Figure 4-1 Serial port connector location

CHAPTER SYNOPSIS

SERIAL PORTS CHAPTER 4

 Overview of RPC-2350 serial capabilities

 Using RS-422/485

 Networking with RS-485

 Preventing program stops (breaks)

 SPI port information

DESCRIPTION

The RPC -2350 has two serial ports that can be used for

interfacing to a printer, terminal, or other ser ial devices.

A SPI port is also pr ovided. This chapter descr ibes their

characteristics and how to use them. Frequent

references are m ade to commands listed in the

CAMBA SIC Programming Manual. Please refer to this

manual for more information.

Serial por ts are num bered C OM 1 and CO M2. COM 1 is

used for program development. It is RS-232 only.

During run time, it can be used for other functions such

as writing to a printer or serial display. COM 2 is a

general purpose serial port. Its outputs can be RS-232,

RS-422, or RS-485 level compatible.

Both ports support XO N/XOF F protocol to contr ol data

transmission. Each por t has a 256 character interrupt

driven input and output buffer. This allows charac ters to

be sent out (using PRINT) without slowing down

program execution. However, if the PRINT buffer fills,

program execution is suspended until the buffer em pties.

Both ports have a 256 character input buffer. When

more than 256 characters have been received, extra ones

are ignored.

The baud rate, parity, data length, stop bits, and com

port type are changed using the CONFIG BAUD

command.

COM1 SERIAL PORT

COM 1 is J1 and is called the Console port on the card.

This port uses a VTC-9F serial cable to connect to a PC

and other external serial devices. The cable is wired

one-to-one, with pin 1 on the 10 pin connector lining up

to pin 1 on the D B-9. T he connector plugs dir ectly into

a 9 pin serial port connector on a PC.

This port is normally used for program ming. D uring

run time it may be used as a general purpose seria l port.

When used for programming or with the INPUT

statement, it will accept ASCII character values from 0

to 127. When used with the INKEY$ and COM$

functions, it returns ASCII values from 0 to 255.

No control lines (like CTS or RTS) are available on

COM 1. A pull up resistor is on the CTS output should a

communication program or device require a positive

indication the port is alive.

COM2 SERIAL PORT

COM 2 is an RS-232, RS-422, or RS-485 por t. It also

uses a VTC-9F serial cable to connect to PC’s and other

serial devices. CO M2 is identical to COM1 except that

it has 2 hardware handshaking lines, CT S and RTS.

NOTE: The CTS output line is low on power up or

reset. This is to prevent the RS-485 transmitter

from turning on and adversely affecting network

communication. RS-232 communication may

be affected by holding off the sender from

sending data. You must enable the CTS output

as described below under “Comm unication flow

control” .

Jumper W4 determines if COM 2 receive is RS-232 or

RS-422/485.

W4[1-2] RS-422/485

W4[2-3] RS-232

Use CONFIG BAUD to tell the system the type and

characteristics of this port. Default is RS-232, 19, 200

baud, 8 data, 1 stop bit. .

1 2 ... 15 16 17 18 19 20 21 22 23 24 25 ... 82 83

Commenti su questo manuale

Nessun commento

Remote-processing RPC-2350 Manuale Utente Pagina 20

Commenti su questo manuale

Prodotti e manuali riguardandi Computer Remote-processing RPC-2350