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Connecting serial devices, Dte versus dce, Db9 serial cables and loopback plugs – Comtrol RocketPort EXPRESS SMPTE User Manual

Page 11: Refer to

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RocketPort EXPRESS SMPTE User Guide: 2000482 Rev. B

Connecting Serial Devices - 11

Connecting Serial Devices

This section provides information about the RocketPort EXPRESS SMPTE
connectors, in the event that you need to build cables or loopback plugs.

A loopback plug is a serial port plug with pins wired together that you can use
with application (for example, the diagnostic, Test Terminal, or minicom) to test
serial ports. See

Before Calling Technical Support

on Page 15 for information

about using the test application shipped with the RocketPort EXPRESS SMPTE.

DTE Versus DCE

Most devices, except modems, are Data Terminal Equipment (DTE) devices.
Modems are Data Communication Equipment (DCE) devices. RocketPort
EXPRESS SMPTE ports are set to DCE by default.

The RocketPort EXPRESS SMPTE conforms to the ANSI/SMPTE 207M-1997
Television – Digital Control Interface – Electrical and Mechanical Characteristics
standard. The Society of Motion Picture and Television Engineers (SMPTE) 207M
protocol permits the control of video and audio tape decks for editing purposes and
can be used to connect controlled device such as, video routers and servers.

DTE and DCE are controlled with the DIP switch on the RocketPort EXPRESS
SMPTE. See

Card and Interface Installation

on Page 7 for information.

DB9 Serial Cables and Loopback Plugs

The following figures and table illustrate the signals present on DB9 connectors if
you need to build your own null-modem or straight-through DB9 serial cables. The
RocketPort EXPRESS SMPTE provides female DB9 SMPTE port connections that
comply with the SMPTE 207M standard so that you can easily connect Sony DB9
type devices.

DB9 Signals

on Page 12

Straight-Through Cables (DCE)

on Page 12

Null-Modem Cables (DTE)

on Page 12

DB9 Loopback Plugs

on Page 12