Operation and Maintenance Manual

Page 6 RF Technology T220
1.1 Front Panel Controls and Indicators 1 OPERATING INSTRUCTIONS
LED Flash Cadence Fault Condition
5 flashes, pause Synthesizer unlocked
4 flashes, pause Tuning voltage out of range
3 flashes, pause Low forward power
2 flashes, pause High reverse (reflected) power
1 flash, pause Low dc supply voltage
LED ON continuously Transmitter timed out
Table 1: Interpretations of LED flash cadence
Indication Fault Condition
Flashing, 8 per second Synthesizer unlocked
Flashing, 4 per second Tuning voltage outside correct range
Flashing, 2 per second Low forward power
Flashing, 1 per second High reverse power
Continuous dc supply voltage low or high
Table 2: Interpretations of LED flash speed, for early models
1.1.3 PWR LED
The PWR LED shows that the dc supply is connected to the receiver.
1.1.4 TX LED
The TX LED illuminates when the transmitter is keyed. It will not illuminate (and
an ALARM cadence will be shown) if the synthesizer becomes unlocked, or the
output amplifier supply is interrupted by the microprocessor.
1.1.5 ALARM LED
The ALARM LED can indicate several fault conditions if they are detected by the
self test program. The alarm indicator shows the highest priority fault present.
Receivers using software issue 5 and higher use the cadence of the LED flash
sequence to indicate the alarm condition. Refer to table 1. Receivers using software
issue 4 and lower use the LED flash rate to indicate the alarm condition. Refer to
table 2.