Patton electronic 1080A, 1080A-64

4.3 FOUR-WIRE, MULTIPOINT INSTALLATION

Multipoint operation involves the connection of several terminals to

one host port. In such an application, one local Model 1080A/1080A-64

is used as a master unit, and it is connected to several remote Model

1080A/1080A-64s that are acting as slaves. Up to 25 Model 1080A

Series slaves may be connected to one host Model 1080A Series

master SRM, provided that the computing hardware and software

support that many terminal drops.

In a multipoint environment the master Model 1080A or 1080A-64

transmits continually. Initiation of two-way communication is carrier-

controlled by each “slave” Model 1080A Series unit. To facilitate

multipoint communication, the master Model 1080A-64 should have its

carrier control DIP switch set to “constantly ON” (S1-8=OFF). Each

slave Model 1080A Series unit should have its carrier control DIP

switch set to “controlled by RTS” (S1-8=ON). Figure 4 illustrates a

typical Model 1080A Series multipoint application.

4.3.1 Multipoint Twisted Pair Connection

The Model 1080A Series supports multipoint applications using a

star topology. Maximum distance between the units will vary based

upon the number of drops, data rate, wire gauge, etc. Call Patton

Technical Support for specific distance estimates. Figures 11 and 12

show how to wire the one-pair and two-pair cables properly for a Model

star topology. Note that the ground connection is not needed.

Figure 4. Typical multipoint set-up

4.4 RS-232 CONNECTION

Connect the synchronous or asynchronous output of your RS-232

device to the DB-25 interface on the rear panel of the Model 1080A

Series. Note: The Model 1080A Series is wired to connect to a DTE.

If your RS-232 output device is DCE, call Patton Technical Support at:

(301) 975-1007; http://www.patton.com; or, support@patton.com

for specific installation instructions.

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