Daktronics Galaxy AF-3190 Series, Display Manual

Page: 9 / 97

Introduction
1-3
The common thread to most client requests is a means of programming and controlling a
group of displays from a central control point. Daktronics responded by developing a
powerful system of interconnecting and controlling displays. Great care has been taken to
design products that will satisfy a wide variety of installations. Some of the design goals
of these systems include the following:
•
Easy transfer of messages
•
The ability to tell a display or group of displays in the network which message
should run
•
The ability to determine the status of any display on the network
•
The ability to control multiple display technologies on the same network
Tools required for mounting the display depend on the location and size of the display.
For some installations, it may be possible to purchase pre-terminated telephone cables for
use with the displays.
There are six (6) network systems available: RS232, RS422, modem, fiber, radio and
Ethernet. Up to 240 displays can exist on one network.
RS232 Network
RS232 (EIA/TIA-232-E) is a standard communication interface that employs a single-
ended serial transmission scheme that uses a maximum cable length of 7.6 meters
(approximately 25 Feet). This interface was designed for computer communication at
short distances. The computer used will require an RS232 communication port. Refer to
Section 3 for additional information.
RS422 Network
RS422 (EIA/TIA-422-B) is a standard communication interface that utilizes a differential
balanced transmission scheme that uses a typical maximum cable length of 1.2 km
(approximately 4000 feet). The main advantage to RS422 over RS232 is the longer cable
length that is possible. A signal converter is needed to convert the computer’s RS232
signal to RS422. Refer to
Section 3 for additional information.
Modem Network
The modem is a standard communication interface that utilizes standard phone
transmission lines. The phone company assigns each phone line a number that the modem
uses to communicate between computer and display. Each modem network needs to
have a dedicated phone line assigned to it. Refer to
Section 3 for additional information.
Fiber Optic Network
A fiber optic network is a standard communication method transmitting light (signal)
through a glass fiber. Fiber optic cable has a maximum length of 600 meters
(approximately 2,000 feet). A signal converter is needed to convert the computer’s
RS232 signal to fiber optic signal; a minimum of two fibers is required. Refer to
Section
3 for additional information.