Microwave Data Systems MDS 4310, Установка, эксплуатация и техническое обслуживание на месте

Страница: 39 / 129

2-12 INSTALLATION MDS 05-2415A01, Rev. A
TRANSCEIVER CONFIGURATION JUMPERS
The 4310 Transceiver has three jumper blocks that configure the transceiver. The following
sections describe the use and function of these jumpers.
J11—TTL/RS-232 and LED Enable Jumpers
Jumper J11 configures two functions; the front panel LEDs and interface signal levels. See
Figure 2-5 and Table 2-4 for jumper details.
With J11 Pins 1–2 jumpered, the
INTERFACE
connector communications pulses are 0 or 5Vdc
and are commonly referred to as TTL. With no shunt across J11 Pins 1–2, U31 is enabled
providing st and -12 Vdc signals on the RS-232 compatible signals available at the
INTERFACE
connector. A shunt across J11 Pins 1–2 disables U31 which is the RS-232 line
driver/receiver IC. With U31 disabled, the signal lines are not converted to RS-232 12Vdc
levels.
The function of J11 pins 3–4 allows the disabling of the LED indicators on the transceiver
front panel. Disabling the LEDs allows less current consumption in solar-powered
installations and other current sensitive installations. With J11 pins 3–4 jumpered the LED
driver IC is enabled and the LEDs function. Conversely, when the jumper is removed from
J11 pins 3–4 the LED driver IC is disabled and the LEDs do not function.
CAUTION
To prevent possible damage to the interface circuitry,
disconnect primary power and the
INTERFACE
connector
before changing jumpers. J11 Pins 1-2 must be shunted if
any of the input/output lines are to be operated at TTL levels.
Failure to do so can damage the transceiver or RTU or may
cause intermittent operation.
J14
RX AUDIO
NORMAL/INVERT
J1
EXTERNAL
INTERFACE
TCXO
FREQUENCY
ADJUSTMENT
J11
RS–232 DISABLE
LED ENABLE
J16
FULL DUPLEX
INTERFACE
3
4
1
2
3 4
1 2
1
2
3
PRINTED CIRCUIT
BOARD MODEL
LABEL
Figure 2-5. Location of Configuration Jumpers