Bird Technologies SCC7 Series-Manual User Manual
Page 24

10
Error Codes
The Bird 4421 displays error codes when the RF power is either below the selected range (underrange) or above the
selected range (overrange). Figure 4 displays the error codes and Figure 5 lists the function limits.
Figure 4 Error Codes
Figure 5 Function Limits
Audible Warning
If the RF power level exceeds 120% of the power sensor’s maximum power capability, the power meter will sound a
warning buzzer.
Symbol
Explanation
Value greater than overrange limit of function
Value less than underrange limit of function
Function
Limit
Error
FWD, RFL
Power > 199.9% of full scale or 120% of top
range
Overrange
FWD dBm, RFL dBm
Power > 120% of full scale
Power < 3% of low range
Overrange
Underrange
SWR
FWD < 20% of low range
FWD – RFL = 0
Underrange
Overrange
Return Loss
FWD < 20% of low range
RFL < 20% of low range
Return Loss > 40 dB
Underrange
Underrange
Underrange