Serial Management; General Information; Types Of Serial Cables; Signal Transmission Over Lightware Extender Devices - Lightware HDMI20-OPTC-TX220-Pro User Manual

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9. Technologies
9.3. Serial Management
9.3.1. General Information
There are two types of devices in general serial communication:
Data Terminal Equipment: Data Terminal Equipment (DTE) is an end instrument that converts user
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information into signals or reconverts received signals. Typical DTE devices: computers, LCD touch
panels and control systems.
Data Circuit-terminating Equipment: Data Circuit-terminating Equipment (DCE) is a device that sits
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between the DTE and a data transmission circuit. It is also called data communication equipment and
data carrier equipment. Typical DCE devices: projectors, industrial monitors and amplifiers.
Among others the pin assignment is different between DTE and DCE.
RD: Received Data (digital input)
TD: Transmitted Data (digital output)
Different type of serial cables must be used between different serial devices.
* In general contact DCE with DCE by tail-circuit serial cable.
9.3.2. Types of Serial Cables
Straight Serial Cable
Straight pin-outs both ends.
Serial cables between devices may have male or female plugs and their type may be straight or null-modem
in usual.
ATTENTION! The cable type does not depend on the plug type.
DTE DCE
RD TD
Pin 2:
TD RD
Pin 3:
DTE DCE
Null-modem Straight
DTE
Straight Null-modem*
DCE
Null-modem Serial Cable
Straight pin-out at the one end and cross
pin-out at the other end (interchange lines
of TX and RX).
HDMI20-OPTC series – User's Manual
9.3.3. RS-232 Signal Transmission over Lightware Extender Devices
The following examples describe the detailed integration of Lightware devices between different RS-232 pin
assignment units.
INFO: Both HDMI20-OPTC-TX220-Pro and HDMI20-OPTC-RX220-Pro are DTE units (according to their pinouts)
with male plugs.
Extending RS-232 between DTE and DCE third-party devices
Connect null-modem serial cable between controller system (DTE) and the transmitter (DTE) and straight
serial cable between receiver (DTE) and projector (DCE).
Controller system
DTE Null-modem
serial cable
Female - Female
Pin 2: RD
Pin 3: TD
RS-232 connection example between a controller system and a projector
Extending RS-232 between DCE and DCE third-party devices
Connect straight serial cable between controller system (DTE) and the transmitter (DCE) and null-modem
serial cable between receiver (DTE) and computer (DTE).
Media Player
Straight serial
DCE
cable
Male - Female
Pin 2: TD
Pin 3: RD
RS-232 connection example between a media player and a projector
Transmitter Receiver
DTE Transmission Straight serial
DTE
cable
interface
Female - Male
Pin 2: RD Pin 2: RD
Pin 3: TD Pin 3: TD
Transmitter Receiver
Straight serial
Transmission
DTE DTE
interface
Female - Male
Pin 2: RD Pin 2: RD
Pin 3: TD Pin 3: TD
65
Projector
DCE
Pin 2: TD
Pin 3: RD
Projector
DCE
cable
Pin 2: TD
Pin 3: RD