Touch Screen Computer Interface Connectors

Touch Screen Interface Connections

Each touch screen connects to your computer through a data cable.
(This cable is in addition to the standard-monitor-video-cable and power-cord).

The touch screen cable has a connector (which attaches to an open port on your computer).
Connector types include USB, Serial, PC-Bus.


USB InterfaceUSB Interface: Short for Universal Serial Bus, an interface that supports Plug-and-Play installation and hot plugging. One cable connects the touchscreen to an available USB port.  Benefits:  Brand new computers often have less Serial ports, and more USB ports.  Limited to 15 feet before requiring signal booster cables.

Dual Serial/USB (Combo) Interface: Provides both serial and USB interfaces.
One cable should be used, NOT both.

    Serial InterfaceSerial InterfaceTouch screen cable connects to an available COM port on the computer.  Serial interfaces may be internal (inside the monitor) or external (mounted outside the computer and requiring an additional power supply).  Touch monitors with internal serial controllers have a female DB9 (9 pin D-shaped) touch output connector.  The connection to the male-pinned COM port is made by a standard male-to-female DB9 cable (modem or mouse type cable).  Benefits:  Cable can be screwed in tight. Extender cables can go 200 feet before requiring signal boosters.
    PC-Bus Interface: (Discontinued).  This model required an expansion card installed inside the computer in an ISA bus slot.  Only some of the older Elo monitors are made to use a PC-Bus controllers - they have a female DB9 (9 pin D-shaped) touch output connector on the card.  The cable is a male-to-female DB9 cable.

Long Cables

A common question is, "How far away from the computer can the touchmonitor be?" The answer, of course, is, "It depends."

Serial cables: The spec on serial cable length is something like, "As far as it can be run without degrading signal quality significantly." In practice, several of our customers have run serial cables 200 to 400 feet without problems.

USB cables: The spec on USB is no more than five meters between powered hubs, five hubs max. So by default you can go approximately 15 feet, and with a single powered hub you can go approximately 30 feet. Powered hubs are a common item, widely available. To go longer distances, you might want to consider a third party USB extender.

Video cables: Six feet is the de facto standard for video cables; longer cable length degrades the video quality unless special cables are used.  You can easily go 50 feet with these cables; here is a supplier of long video cables. Video amplifiers are also available from third parties.