RFL 9780 RFL Electronics Inc.
November 1, 2000 7-10 (973) 334-3100
7.5.1.3 TRANSMITTER POWER LEVEL LOGIC CIRCUIT
The outputs produced by the trip-input circuits and optional voice module are fed to the transmitter
power level logic circuit. The configuration of the 9780 Tx Logic Module determines how the logic
circuit will react to the inputs. The transmitter power logic circuit generates the A SWITCH and B
SWITCH outputs which are located at edge connector pins A14 and B14 respectively. The transmitter
module uses these to control the output power level. The following table defines all valid states of these
signals:
Table 7-8. Transmitter power levels
A_SWITCH B_SWITCH POWER LEVEL
0 0 10W
0 1 10W
1 0 3W (Voice)
1 1 1W
7.5.1.4 TRANSMITTER VOICE CONTROL LOGIC CIRCUIT
This feature is used with the voice option, which is not being offered at this time.
7.5.1.5 TRANSMITTER FAIL ALARM CIRCUIT
The HI signal applied to edge connector pin A16 is received from the power amplifier module. In the
non-alarm state, an open-collector transistor is turned on which drives the TX_FAIL signal low,
energizing the transmitter fail alarm relay. If the HI signal input is logic-high for a period greater than
125µs, the open-collector transistor is turned off. This drives the TX_FAIL signal high, de-energizing
the transmitter alarm relay. The TX_FAIL signal is held in the de-energized state for an additional
150ms once the HI signal returns to the normal logic-low state. DS8 lights in the transmitter fail alarm
state. The status of the transmitter circuit is recorded by the sequence of events module.
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