The CLI command siglevel can provide in depth detail of some link parameters that are not shown elsewhere. This can be especially useful for troubleshooting RF performance issues as well as checking for any issues that may not be evident with the output from linktest.
While the exact functions included in each device and build may vary, this information will be helpful in diagnosing poor link conditions or telling if the link is performing within tolerable ranges.
IDU RSSI: -11
Typical -8 to -11 for short cables.
Will decrease the longer the cable as the ODU maintains the same output power (-10 dBm+/- 2 dB). Typical values based on cable length: 0’ -10, 100’ -12, 250’ -14, 500’ -17, 1000’ -25.
Normalized MSE: -324
Radial MSE: -323
Expressed in 1/10th of dB. -324 = -32.4 dB. Under normal operation, MSE should be -32 or better. -29 is a worse number.
Norm‐MSE = Radial MSE phase noise residue is minimal
Norm‐MSE > Radial MSE there is some amplitude noise (AM distortion)
Norm‐MSE < Radial MSE phase noise residue exist, that the PLL did not fully correct
LDPC Decoder Stress: 0
This is the forward error correction engine correcting impairments to the signal caused by normal channel multipath, radio phase noise, noise in the channel, and non-linearities in the power amplifier and receiver circuitry. Ideally should be zero, but may burst to the hundreds or thousands occasionally and still be considered normal. The greater the number the harder the decoder is working.
External AGC: 1652
This is the IDU/OMU modem control voltage that sets the correct signal level into the Analog to Digital Converter in the receiver chain. Based on the level of the 140 MHz Receive IF coming into the IDU/OMU, this value will change. It is directly mapped to the IDU RSSI value.
Carrier Offset: -22393
How far off the center frequency is from expected, expressed in Hz. Closer to zero the better. Normal range is within +/- 5 ppm (parts per million Hertz) of the set frequency. If set frequency is 10 GHz, and the outside limit is 5 x 10,000, or +/-50 kHz. For higher frequencies the outside limit will be higher.
Rx Symrate: 17422930
This is the symbol rate that the receiver has locked onto and is tracking. It should match the set transmit symbol rate from the speed command very closely. If this number is changing or is not close to the Transmitter set rate then there may be a physical problem with the ODU or IDU.
Block Counter: 0
Accumulated data blocks received since last link establishment. Collected on a 20 second periodic basis, and cleared when read using the siglevel command in older firmware. In current firmware it is cleared with <status clear>.
Uncorrect Block: 0
Accumulative demodulated data block errors since last link establishment. Collected on a 20 second periodic basis.If non-zero there are packets being dropped over the RF link. Errors reported by modem when passing traffic. Should be 0. Use <status clear> to reset the counter to 0, which must be done after link establishment as this will always result in some uncorrected blocks. This value can also be read via SNMP.
LDPC Avg Iteration: 0
Average of the LDPC Stress Decoder reading.
Output corrected bytes: 0
Number of bytes that the LDPC decoder was able to correct using forward error correction.
Return Loss: 0x07D6
Analog measurement of the reflected energy on the IF cable used to detect severe mismatch on the cable.
Power sensors
Used to check accuracy of transmit and receive. Supported items vary from ODU to ODU.
Tx Power alarm: ok
State is OK or alarmed. Should be OK under normal operation.
Tx PA alarm: ok
State is OK or alarmed. Should be OK under normal operation.
PA on/off alarm: on
State is on or off. Should be on under normal operation.
Tx Power Range alarm: ok
State is OK or alarmed. Should be OK under normal operation.
Tx Power actual: 15.00
Should match within a few dB of the set transmit power.
Rx Power actual: -41.00
Channel test: Pass
Telemetry debug: Pass
Apex specific
TX power attn: 0x00
RX power rangeattn: 0x00
Shows how much attenuation the odurxagc is adding to the signal. Useful to check this when RSSI is low or MSE is lower than expected for given RSSI.
Tx Power: 10.0 dBm
Shows current set tx power.
Tx Power Raw on IF: 0xB4, 0x09
Tx Power Raw on RF: 0x71, 0x01
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