RFL Electronics 9780 - Table 7-7. Valid States of 2 F and 3 F Signals for Trip Down and Trip Up

RFL 9780 RFL Electronics Inc.
November 1, 2000 7-9 (973) 334-3100
A logic-low TRIPSENT_RLY signal will energize the trip sent relay when a trip condition is keyed in
2F and 3F systems.
TRIP IN 1 LED indicator DS6 and TRIP IN 2 LED indicator DS7 light when corresponding trip inputs
are keyed. Optionally, the 9780 Logic Module can be configured to keep the trip sent relay energized
after a trip has been keyed. The relay can be de-energized with the TRIP RESET button on the front of
the module.
Optionally, the 9780 Logic Module can be configured to latch the DS6 and/or DS7 indicators for a trip
condition depending upon the system. The LEDS are reset with the TRIP RESET button on the front of
the module.
The status of the TRIP IN_1 and TRIP IN_2 inputs are recorded by the sequence of events module.
7.5.1.2 TRANSMITTER FREQUENCY LOGIC CIRCUIT
The outputs produced by the trip-input circuits are fed to the transmitter frequency logic circuit. The
configuration of the 9780 Logic Module determines whether one or both trips must be present before a
valid trip is accepted by this logic circuit. The transmitter frequency logic circuit generates the OSC1_2
and OSC3 outputs that are located at edge connector pins A13 and B13 respectively. The transmitter
module uses these signals to control the output frequency for 2-frequency (2F) and 3 frequency (3F)
systems. The trip frequency can be configured to trip “up” or trip “down” in accordance with the setting
of SW2-1. The Table 7-5 defines all valid states of these signals for 2F and 3F systems:
Table 7-7. Valid states of 2F and 3F signals for Trip “Down” and Trip “Up’
OSC_3 OSC_12 TX FREQ TRIP “DOWN” TRIP “UP”
2F 3F 2F 3F
0 0 F1 DTT / START DTT GUARD / STOP UNBLOCK
0 1 F2 N/A (CF) GUARD / BLOCK N/A (CF) GUARD / BLOCK
1 0 F3 GUARD / STOP UNBLOCK DTT / START DTT
Under normal power conditions, a logic-low CARRIER_ENABLE signal is applied to the Transmitter
Module, allowing it to respond to the frequency control signals. However, during under-voltage
conditions, a logic-high CARRIER_ENABLE is applied to the Transmitter Module, preventing it from
responding to the frequency control signals.