BUC status in iDirect VSAT system

Hi, I've been working with an iDirect 5000, mainly through telnet.

On the back panel there is a light called BUC PWR, and in the iSite software there is a section called BUC status. These seem to be related, if BUC status = Ok the light is on, if BUC status = Fail the light is off.

I just cannot find a command to check the BUC status/PWR via telnet.

Any help would be much appreciated.

Thanks

Hi Eric, You are completely right with the BUC PWR LED. Compared with documentation I've found.

I tried alot of commands from typing "help" and I also found a pdf with every command with occasssional descriptions, but no luck so far.

https://www.livewire-connections.com/sites/default/files/files/documents/Hardwar...

I'm using the command tx iflDC to turn the Led on and off. But it doesn't prevent turning on if the the BUC status fails (LED doesn't turns on).

It was suggested to me that the command rxdiag txcurrent effects it. The tests i tried found this:

BUC OFF = BUC Status Ok
BUC ON && Current < 0.22 = BUC status fail
BUC ON && Current > 0.8 = BUC status Ok

I couldn't get the value between 0.22 and 0.8.

I then asked a colleague on the results they found and they got something completely different.

Current < 0.02 = BUC status Ok
Current > 0.03 = BUC status Fail

I'm not sure if rxdiag is to do with the BUC, I can't find any documentation.

Thanks for your time

No such luck with txdiag. I thought it would be a commmand but apparently not.

I think the power of the BUC should increase as well. So if Power = Volts * current, so then if current is more, power will be more. This doesn't work for the second lot of test data. Unless maybe it's receiving too much power?

The testing we did was with tampering the connectors to get fail results, we also tried with 9 BUCs (3 different models) to try and find a correlation.

Think I'm going to have do run some more tests.

I tested changing the TX Power, but I didn't find it very useful so I didn't include it. Here it is:

BUC Ok:

     TX Pwr          Volts     Current
     -35              23.52      0.93
     -34              23.52      0.96
     -33              23.52      0.96
     -32              23.52      1
     -31              23.52      1.05
     -30              23.52      1.13
     -25              23.41      1.45
     -20              23.29      2.2
     -15              23.19      2.49
     -10              23.19      2.57
       -5              23.19      2.59
        0              23.08      2.67
        5              23.19      2.66

BUC Fail:

     TX Pwr        Volts      Current
     -35              23.73      0.2
     -34              23.73      0.2
     -33              23.73      0.2
     -32              23.73      0.2
     -31              23.73      0.2
     -30              23.73      0.2
     -25              23.73      0.2
     -20              23.73      0.2
     -15              23.73      0.2
     -10              23.73      0.2
       -5              23.73      0.2
        0              23.73      0.2
        5              23.73      0.2

This helped to support my first hypothesis. Other than that it didn't show me anything. (Only tested with one BUC)

When we ran this test we did all the safety stuff. Marked a radiation zone and stayed clear. We also aimed away from the satellite belt to avoid causing any issues to anyone else. I was also told the BUC could go to the power without any issues.

You are right though, I probably should have mentioned these warnings before in case anyone happened to come across this and attempt to replicate.

What model of iDirect router do you have and what model of BUC ?
I hope someone can help you.

Best regards, Eric.

Some characteristics of the NJT5669F BUC:
RF output power: +37 dBm (at -1dB gain compression point)
Gain: 61 dB
DC volts: +24V (+15V to +30V) DC
DC power: 48W max
Mute (therefore no output power): LO unlocked or no 10MHz reference
LED indicator: Green = LO locked. RED: LO unlocked or no 10MHz reference
Note: No mention of any telemetry.
Is the BUC LED showing green ?  Is the 10 MHz reference supply activated ? Is there anything in the IF cable that is blocking 10 MHz?

I don't know if the X3 or X7 modem have the ability to measure the DC volts and DC current being fed to the BUC.  If anyone can help please say here.

Meanwhile you might consider making up a test rig with male/female F connectors and a resistive tap and measuring the voltage using a voltmeter. Measure the resistance of the IFL cable and repeat the voltage measurement at the other end. Calculate the current.

It is particularly important to follow exactly the section about "1 dB Compression Point and Maximum Power" in the user Manual.

Plot your graph of Pout versus Pin, with help from the NOC, like the example above for a 3W BUC ( 3W = +5 dBW = +35 dBm)
This example is from the iDirect User Manual, which you should follow.

Always start with lowest modem output level and increase slowly in 1 dB steps until the NOC can see your CW carrier on the correct frequency, correct polarisation and correct satellite!.

Set the modem output level for the P1dB compression point as the maximum allowed modem output level. I cannot stress too strongly that you must not allow the BUC to go beyond the -1dB compression point as this will degrade the error rate of your own signal and cause interference to others. Only very few models of BUC (such as expensive higher power types) have protective power limiting circuits that quickly trip out to Mute if an excessive input level is applied. Hopefully the trip off is fast enough to prevent permanent damage to the output transistors.

Please what command can I use to increase or reduce BUC Tx power?