iSite and the iDirect Option File

The iDirect modem has an option file that configures the modem for the satellite network that you will access. The option file is generated by the satellite service provider and either “pushed” to your modem over the network by the NOC, or loaded locally, using a program called iSite.

If you have a green receive light on the modem, the NOC will be able to transmit or “push” a revised option file over the satellite network to your modem. You just need to call the NOC, tell them what satellite you are tracking and ask them to push the new file.

The NOC will periodically push revised option files, as required, when network changes are made. If, for some reason, the network changed while your terminal was offline, or if you are changing to a new area of operation, and you do not have a green receive light on the modem, the NOC will have to send the option file by email, and you, or a technician will need to load the option file, into the modem using a program called iSite.

It is important that you have the correct version of iSite for the level of software that is loaded in your modem, although, in an emergency, some incorrect versions of iSite have been known to work OK.  Check with the network operator.

Connecting the PC to the modem

The PC running iSite must have network access to the modem, via WiFi, via the ship’s router, via a switch connected to the modem, or by directly connecting the PC to the modem LAN port.
iDirect Network
If you know the IP address of the modem (which on good installations will be on a label on the front of the modem), try to ping the modem address. If you do not get a reply from the modem, then you do not have access via the network or via the WiFi.

The satellite provider Network Operations Center (NOC) should be able to supply you with the IP address and the password for the modem.

If you do not have the modem IP address, you can open the option file with Wordpad, and scroll down until you find
lan_ip =
Be careful not to save any changes to the option file when closing it.

If there is a network switch connected to the LAN port of the modem, you can try to connect the PC with an ethernet cable via the switch.

Otherwise, you will need to connect the PC directly to the modem LAN port while loading the option file. Remove the current LAN connection from the back of the modem and connect the PC in its place.

If your PC Local Area Connection is set to obtain an IP address automatically, and the modem LAN port has DHCP, then you should be able to ping the modem. If not, you will need to set the IP address of the PC’s ethernet Local Area Connection (not WiFi) at one digit above the modem IP address. For example, if the modem is, you would set the PC to

When using an ethernet connection, it is advisable to shut down the WiFi on the PC to avoid any conflict. In some cases, it helps to turn off windows firewall.

When properly connected, and the PC can see the modem gateway, the Local Area Connection should show up as a valid network.

When you can successfully ping the modem, you are ready to run the iSite program or telnet to the modem.

Loading an option file with iSite.

iDirect iSite Login

Start the iSite program and watch the window on the left, where the program should recognise the modem and show its serial number and IP address. There might be some other addresses in the window from previous modems, or from the software default. These can be deleted by right clicking on them and clicking Delete.

If your modem does not show up in the window, you can right click where it says iDirect and click “New”, then right click the new modem and click Login, and enter the modem IP address and password.  If the modem shows up, right click and Login and enter the password from the service provider. In most cases, admin should be checked and Secure Connection.

Once connected, hover the mouse over the icons in the menu until you see Upload Option to Disk. It is a good idea to get the existing option file off the modem in case you need to reference information in the file, or reload it. Put the old file somewhere safe on your PC and label it old. It will download and automatically open in Notepad, which often does not recognize the formatting. It is best to reopen it in Wordpad if you need to inspect the file.

iDirect iSite

Locate the new option file on your PC. Again, in iSite, hover your mouse along the icon menu until you see Download Option File From Disk. Browse to the new option file and make sure it is the right file. Beware of uploading the wrong file, as you can “brick” the modem.

iSite will ask if you are sure that you want to download it, so click     Yes      and it should quickly say “Download successful Reset reguired“. Click   Reset Now    and the modem should reset and load the new file.

The terms Upload and Download are sometimes confusing but remember that the modem (not the PC) is uploading and downloading, but the key to watch is From Disk and To Disk referring to the PC hard drive.

Beamselector commands

1. Start Command promptStart/Run cmdOn your PC go to START/ RUN and type in cmd and  or type cmd into the search box.
2. Telnet to modemC:/users/mypc>telnet the DOS prompt in the command box, type in
telnet and
using your own modem ip address.
If telnet does not run, you will need to enable telnet on your PC.
3. Enter usernameUsername: adminIf you do not get the user prompt, you may not have network access to the modem.
4. Enter passwordPassword: *********You need to get the password from the service provider
5. Modem responds[RMT:90625];49220
LAT-LONG : [LAT = 25.766N LONG = 80.182W]
Your modem response will be different. The modem will keep outputting these strings.
Ignore the modem output while you type in the next commands,
or you can stop the output by typing
6. Beamselector list>beamselector listType beamselector list and <enter>
7. Modem responds142 is currently selected
136 = T14R @ 63W Atlantic
142 =T11N @ 37.6W Caribbean
145 = T12 @15W Europe
Modem shows the current beam and available beams
8. Switch beams>beamselector switch 136 -fType beamselector switch <beam number>  -f and <enter>
9. Modem responds and restartsEnter switch to new beam function
Switching to beam “NT14R @63W Atlantic” based on Console command
> Scheduling Service Restart
Modem Demod is unlockedConnection to host lost.
If openAMIP is enabled, the modem will command the DAC to switch to the new SAT, FREQ and POL.
If openAMIP is not enabled, you will need to enter the satellite parameters on the antenna controller manually.
 10. Beamselector lock>beamselector lock Type beamselector lock and to stop modem switching beams.
The beam will stay locked until the modem is reset


To Enable Telnet on your PC

If telnet is not enabled, your PC will respond that telnet is not a recognized command.

To enable telnet on a Windows PC, go to START/ CONTROL PANEL/ Programs and Features then click Turn Windows features on or off.  Scroll down the list to find Telnet Client and put a check mark in the box.

To ping an IP address

From the command line or DOS prompt, type
C:/user/mypc> ping or whatever the address might be.
The modem should respond with four successful pings something like the following:
Reply from bytes=32 time=94ms TTL=45
Reply from bytes=32 time=94ms TTL=45
Reply from bytes=32 time=94ms TTL=45
Reply from bytes=32 time=94ms TTL=45

VSAT Technology Features
In this post we will be focusing on VSAT technology features to familiarize you with what VSATs are and their many applications for connecting to the Intenet via satellite or for forming a private network over satellite. VSATs are small earth stations (normally 1.2 – 2.4 meters) that are utilized for reliable transmission of data, voice and video via satellite. VSAT Terminal Equipment consists of two units – an indoor unit (IDU) and an outdoor unit (ODU). The outdoor unit is placed outdoors for a line-of-sight to the satellite and the indoor unit interfaces with the user’s communications device (e.g. data terminal equipment such as a network switch or router).

VSAT Installation

VSAT Installation

In this VSAT Installation Guideline we will walk you through the various steps in a VSAT installation:

Ground mount:

This involves a tube/pipe lowered into a hole which is then filled in with concrete.  Alternatively the tube may have a metal base plate attached so that it may be screwed to a plain concrete base using expanding bolts or similar.  The pole should be accurately vertical so that when you swing the dish around to find the satellite the elevation angle stays the same all the time.

Securing the area with fencing or similar may be necessary.


Non penetrating mount:

Based on an angle iron frame covered in concrete slabs.   The antenna support tube is held vertical by several angle braces. Make sure that all angle braces are tight so that the pole does not wobble or twist in the wind.  Read the assembly instructions carefully.  The lower and upper angle braces may need to be attached to opposite sides of the vertical pole to prevent twisting.

A permanent safety rope is advised to be attached between the dish assembly and some fixed part of the building so that the dish does not blow off the building in exceptionally high winds.

Check the building roof is strong enough to support the weight of all the concrete blocks.  In many cases a non-penetrating mount is not possible due to weak roof.


IFL Cables

One or two coax cables will be required for the radio signals.  These also carry low voltage DC supplies to power the LNB and BUC.  The centre pin of the F connector must stick out about 2 mm.   The outer braid of both coax cables must be well connected at all four ends.   If the outer braid of one coax cable is disconnected somewhere there will be very strange effects.

The antenna structure should be earthed to provide some protection from lightning strikes. If the building uses PME type earthing then consult a competent electrician regarding the lightning earth connection as there is a risk of hazard if an electricity network fault arises.  In some countries useful regulations exist and provide guidance on how to earth the antenna safely.

Take care connecting up both the coax and earth cables as there may be differential earth voltages at each end.   A thick earth cable between the antenna structure and the indoor chassis unit should make it safe to connect up the coax cables.   If in doubt use the outer of one coax to make contact between the indoor unit chassis and the antenna before plugging in the other coax, noting that the centre pin of the coax may connect up first before the outer.


The indoor data processing unit (IDU) or satellite modem

The indoor data processing unit (DPU) should be located in a dry, cool and clean place.



Installing a dish is normally dangerous. Take care not to fall down and not to drop tools on others below. Be careful with ladders – always tie off the top to some secure point. A small electric shock may make you fall off a ladder so be extra careful.

If you are a beginner, practice the complete VSAT installation at ground level before moving everything to the roof.


Accuracy of dish pointing and polarisation alignment

The dish pointing (azimuth and elevation) needs to be near perfect (within the -0.25 dB of the beam peak on transmit) as the transmit beam is narrower then the receive beam.

The feed rotation polarisation adjustment needs to be to 1 deg accuracy to ensure that you are in the very sharp null.  Make this adjustment very slowly while the hub staff watch the CW signals on their spectrum analyser.  Give the hub staff plenty time to make each measurement (20 seconds) and then rotate the feed a fraction while talking to them.  They are looking for a signal about 25 – 35 dB down so it is not easy.



Azimuth and Elevation

What is Azimuth and Elevation? How can I calculate them?

Azimuth refers to the rotation of the whole antenna around a vertical axis. It is the side to side angle. Typically you loosen the main mount bracket and swing the whole dish around on this vertical axis to achieve a particular azimuth.

Elevation refers to the angle between the beam pointing direction, directly towards the satellite, and the local horizontal plane. It is the up-down angle.

You can calculate Azimuth and Elevation here: