Connecting to an OxTS INS using Ethernet

Introduction

Ethernet communications between an OxTS INS and a PC use two protocols, UDP and FTP.  UDP is used to carry the live navigation output from the INS in the form of the NCOM data stream and FTP is used to transfer the configuration files to and from the INS.  There are certain requirements that must be met for these communications to be successful.

PC configuration

The NCOM data stream from the INS is carried as a UDP broadcast (packets are sent to the special IP address 255.255.255.255) and may consequently be received by any connected PC.

Configuration files are transferred using FTP, which requires that the sending and receiving devices are both in the same subnet.  For successful FTP transfer, the IP address of the PC must therefore be in the same address range as the INS, but the IP address of the PC must be different to all other devices on the network.  For example, if the network consists of just the PC and the INS, the following IP addresses would be OK:

INS = 195.0.0.17     PC = 195.0.0.160

The IP address of the PC can be changed in the Network & Internet settings as follows:

select Change adapter options;

right click on your Ethernet connection and select Properties;

from the list of protocols in the Ethernet Properties window, select Internet Protocol Version 4 (TCP/IPv4);

in the IPv4 Properties window, select Use the following IP address and enter a suitable address;

after entering the IP address, press the Tab key and the Subnet mask field will automatically complete itself;

no settings are required for DNS server addresses when communicating with your INS, so you can now click OK to exit these windows and save your new settings.

Firewall settings

Communications can be blocked by a firewall in your PC, so the NAVsuite applications should be permitted access through the firewall.  When you first use a NAVsuite application, you should be asked to give the application this permission, which you should accept.  However, if you subsequently connect to the PC when you are connected through a different type of network (either Domain, Private or Home), your access might be blocked by the firewall.  This can be controlled in the Windows firewall by opening Windows Defender Firewall with Advanced Security, scrolling down the list of Inbound Rules to find the applications in the OxTS group, then double-clicking each of the applications in turn to open the Properties window.  In the Advanced tab, the different types of network for which access for the application is required can be ticked.

While this window is open, you should also check in the Protocols and Ports tab that the required protocols are not blocked.  FTP is part of TCP, so the required protocols are UDP and TCP, though the latest NAVsuite installer will fix the protocol field to Any.

Other possible issues

Routers

Another possible cause of Ethernet communication problems is the use of routers in the network that might block broadcast UDP packets, meaning that the NCOM stream would not be visible to the PC.  In a normal in-vehicle installation, this is very unlikely to occur.  If you experience such a problem and you cannot configure the router to permit UDP broadcasts, please contact our Support team with details of the exact network configuration.

Stream selection

If an INS has been configured to output MCOM data, when opening a template in NAVdisplay to monitor the output, the data stream might not be shown because the template was created to use an NCOM data stream.  If you encounter this problem, please use a template designed to connect to MCOM data, or add your own widgets to display the data from the INS.  The latest version of NAVdisplay is able to connect MCOM data to the standard templates.