Bird Technologies MSCC7 Series-Manual - Manual (Page 22)

Bird Multi-Sensor Cal Cart System
8
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 5
displays the error codes and Figure 6 lists the function limits.
Figure 5 Error Codes
Figure 6 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