ZETRON 640 DAPT XTRA, Руководство по установке и ремонту

Страница: 79 / 210

Installation
025-9416 67
•
combination (local and remote transmitters)
The following subsections overview the basic connections between the Model 640 and a variety
of common RF equipment — transmitters, controllers, and link equipment.
Modifications For TTL Data Outputs
In some system applications, RS-232 data output levels are not desired for the radio station
connections. If either the DIG DATA (pin #42) or the DIG MODE (pin #14) signals need to be
pulled down for TTL data, insert the simple circuit shown in Figure 29 between the Model 640
output and the transmitter input.
+5V
TTL level
output to
transmitter
3.3k
Ω
¼W
10k
Ω
¼W
Data output
from Model
640
Figure 29. RS-232 to TTL Data Level Conversion
RF Station Jumper Settings
The Model 640 uses jumper settings and potentiometer adjustments to provide the needed radio
station output flexibility. The jumpers on the peripheral motherboard control RF broadcast
station interface parameters.
Note: Improper jumper settings can result in pager decoding errors or poor audio quality.
Figure 30 shows the locations of each jumper on the peripheral processor circuit board.
JP10
JP8
a
b
JP7
JP
b
a
JP5
b
a
Front of
Model 640
Chassis
⇒
JP4
b
a
JP3
JP6
b
a
JP2
b
a
JP
1
a
Figure 30. Peripheral Board Jumper Locations (Top View)