The starting point for an active iDirect connection is the RX indicator, which must be green, and you must have an RX SNR greater than 6. This article assumes that you have installed the iDirect Modem Tool iDModTool. If not, you can read about it and download here.
Troubleshooting a poor RX connection when the the DataStorm controller (positioner) indicates that pointing has completed, but you still don't have a green RX light and/or you do not have an SNR value of 6 or greater (as displayed in iDModTool):
- if SNR is a positive number greater than 2 then look to trees or other obstructions, snow on the dish, condensation in the feed horn and the usual things that limit signal quality.
- If the SNR is -100 indicating that the IDirect modem does not see the satellite at all, then check the configuration of the positioner and verify correct satellite and polarization. If uncertain try vertical transmit and horizontal receive.
- Check the back of the IDirect modem for red lights. Cycle power if any red lights are seen.
- Now check the configuration of the modem. From the iDmodTool, lower center of the screen, check the Rx Freq and compare this to what you had when you last got the system working. If you don't have that number, call your service provider and ask for the outbound carrier frequency. If it is incorrect then ask your provider to e-mail a fresh option file to you. You will need the iSite program to install it.
- Turn off the power on the positioner and verify the LNB indicator is still on. If not, check cabling to the modem. Verify that the two coaxial cables on the back of the positioner are not reversed. Check also that the cable from the positioner is plugged into the modemís Rx input. Not to be confused with the Rx output that should have a silver cap on it.
- Finally, disconnect the coaxial cable that leads to the roof from the back of the positioner and connect that directly to the modem Rx input. If this works then a defective positioner is indicated.
Troubleshooting a solid RX lock that won't transmit: TX should be blinking green. The iDmodTool is helpful here because it will adjust transmit power until you are connected. Assuming the hardware is working, there are only three reasons that you cannot connect.
After all this, and 20 min. of watching iDmodTool adjust your Tx power, then you must consider hardware. The easiest way to check the transmitter, if you have Rx lock, is to call your provider and ask him to command a CW test signal and watch for it on a spectrum analyzer. It takes about 10 minutes , and verifies transmitter operation from modem to BUC. While you are there, he might want to do a 1db compression test. Some older BUCís like the NJT5017(f) are subject to drastically reduce power if driven by excessive power from the modem. Simply, the modem calls for a little more power and gets a lot less. Your provider can set your MaxTxPwr, if this is the case.
- The account is disabled at the NOC.
- The transmitter power is too high or too low. iDmodTool will continue to adjust both up and down until you are connected. Again, check the back of modem for red lights. If any, reset power. If red light persists, then check transmitter and cable.
- The latitude and longitude, while not important for receive lock, is critical for transmit. If this is a fixed site or you have used manual override then check setting. Degrees and at least two decimal positions are required. Some versions of the positioner firmware would allow the positioner to begin pointing using the last known position after a timeout. This is okay if you have not moved.
If you are having trouble staying online, check all the above. On the iDModTool, if the TxPwr bar graph display stays all the way to the right, max power, then consider a bigger dish, bigger BUC or lower bandwidth uplink connection. Your provider may move you to a different in-route.
About the author: John is a fulltime RVer, programmer and iDirect user. At the time of this writing he is providing customer technical support for Ethersat iDirect users.