Impulse 3087 Manuel d'utilisateur télécharger pdf (Page 11)

Technical Description

Sealevel Systems COMM+2/EX Page 8

Technical Description

The COMM+2/EX adapter utilizes the 16550 UART chip. This chip features programmable baud rate, data format,

interrupt control and has a 16 byte transmit and receive FIFO.

Features

• Fully independent operation of ports allowing two ports RS-232, two ports RS-422/485 or one port of each.

• Addressable as COM1: - COM4: or any other I/O address up to 3FF Hex.

• ‘Shareable’ IRQs allow more than one port to share a single IRQ provided the proper driver is used..

• IRQs 2/9-5, 7, 10, 11, 12, 15 supported

• Support for non-standard baud rates available. These baud rates (such as 31.25K or 76.8K baud) are

supported by installing a different oscillator. Please consult Sealevel Systems Technical Support for more

information.

Line Termination

Typically, each end of the RS-422/485 bus must have line terminating resistors. A 100 ohm resistor is across each

RS-422/485 input and a 1K ohm pull-up/pull-down combination bias the receiver inputs. If more than two RS-485

nodes are configured in a multi-drop network, only the nodes at each end of the bus should have the 100 ohm

resistors installed.

Connector Pin Assignments

RS-232 (Male DB9)

Name Pin # Mode

TD Transmit Data 3 Output

RTS Request To Send 7 Output

DTR Data Term Ready 4 Output

GND Ground 5

RD Receive Data 2 Input

DCD Data Carrier Detect 1 Input

DSR Data Set Ready 6 Input

CTS Clear To Send 8 Input

RI Ring Indicator 9 Input

Note: These assignments meet EIA/TIA/ANSI-574 DTE for DB-9 type connectors.

RS-422/485 (Male DB9)

Signal Name Pin # Mode

GND Ground 5

TX + Transmit Data Positive 4 Output

TX- Transmit Data Negative 3 Output

RTS+ Request To Send Positive 6 Output

RTS- Request To Send Negative 7 Output

RX+ Receive Data Positive 1 Input

RX- Receive Data Negative 2 Input

CTS+ Clear To Send Positive 9 Input

CTS- Clear To Send Negative 8 Input

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Impulse 3087 Manuel d'utilisateur Page 11