BIRD Thruline 4028A250K, Operation Manual

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Operating Instructions
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).
Table 1 displays the error codes and Table 2 lists the function limits.
Table 1 Error Codes
Table 2 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 Overrange
Power < 3 % of low range Underrange
SWR
FWD < 20 % of low range Underrange
FWD – RFL = 0 Overrange
Return Loss
FWD < 20 % of low range Underrange
RFL < 20 % of low range Underrange
Return Loss > 40 dB Underrange