Daktronics Galaxy Series, Manual

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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
There are five (5) network systems available: RS232, RS422, modem, fiber, and
radio. 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. Most computers have an RS232 communications
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 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 at the computer uses to communicate to the modem in the 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 are required.
Radio Network
The Radio network is a standard communication method that uses radio waves at
high frequencies to transmit signal. The Venus 1500 Radio network has a maximum
distance of 450 meter (approximately 1500 feet) outdoor and 150 meters
(approximately 500 feet) indoor. A nearly straight line-of-sight path must be
maintained between the server radio connected to the computer and the client radio
connected to the display. Refer to
Section 3 and the Venus 1500 Radio Manual,
ED13932 , for additional information.