Specifications

MDS 05-3438A01, Rev. E MDS 4790/9790 Series I/O Guide 23
Orderwire Connector—J9
The radio provides for an orderwire channel to facilitate communica-
tions between two associated MDS 4790/9790 radios. The jack accepts
a standard telephone handset with a carbon microphone and with an
RJ-11 connector-equipped cable. See Section , Coordinating Activities
by Orderwire, beginning on Page 25 for further information.
Alarm Contacts—J10
J10 is a plug-in terminal strip that provides connections for optional
alarm circuits. Figure 22 shows the function of each terminal as viewed
from the rear panel.
Terminals 1 and 2 provide solid state relay contacts that close when a
minor alarm is detected. Terminals 3 and 4 provide relay contacts that
close when a major alarm is detected. These relay contacts may be rede-
fined if necessary via the radio’s software (switched from minor to
major alarm outputs, or vice versa). The
ASENSE command is used to
change the relay contacts from normally open (
NO) to normally closed
(
NC). The contacts are rated for non-inductive loads up to a maximum
60 Volts (AC or DC) at 1 Ampere.
Invisible place holder
Figure 22. Alarm Relay Connections
19 OUT 14.0 Vdc Output. Provides a regulated supply
voltage at 1.5 amperes for low-power accessories.
20 -- No Connection
21 -- No Connection
22 -- No Connection
23 -- No Connection
24 -- Do not connect—Reserved for future use.
25 -- No Connection
Table 4. Data Interface Pinout (Continued)
Pin Num-
ber
Input/Output Pin Description
MAJOR ALARM
RELAY
(NORMALLY OPEN)
MINOR ALARM
RELAY
(NORMALLY OPEN)
4123 5 6
PINS 5 &6 RESERVED FOR
FUTURE USE—DO NOT CONNECT