A Guide to Field Day Network Logging

Adopting and evolving electronic logging for Field Day can been a slow journey for many clubs given trusting technology with their precious logs. The journey often looks like:

• Standalone - Clubs standardize on a software package used by all stations. Station logs are collected and compiled into a single log file with some post-processing (manual)

• Standardized - Clubs standardize on a software package used by all stations. Station logs are collected and compiled into a single log file with some post-processing.

• Networked - Clubs use network version of their standard software package. Single log file pulled from server with some post-processing.

The key to evolving computer logging solutions is focusing as much on process as you do on the technology. 

When I say process I am speaking to building mature, repeatable processes in implementation and documenting them in sufficient detail that the passing of "tribal knowledge" is not required. This documentation also needs to be updated and tested every year before Field Day.

This article focuses on networked using the N3FJP ARRL Field Day Contest Log software in a wireless network configuration that uses a Raspberry Pi 3 Model B+ as a Windows File Share, Web, and Logging server. 

This Field Day Network logging solution has been in use for six consecutive Field Days by the Orange County Amateur Radio Club with no loss of data.

Network Considerations

Latency is your enemy. The N3FJP ARRL Field Day Contest Log (hereafter referred to as "the software") is sensitive to latency given it's use of Microsoft Access MDB file format for the log file and the "chattiness" of the Microsoft SMB network protocol it uses. 

Plan and test your wireless network coverage. Not all wireless cards in laptops are created equal. Low signals will yield significant packet loss and retries adding to latency. 

This needs to be discussed as part of the site layout planning for stations and antennas. Also be cognizant of any potential sources of interference especially at sites with RF sources not part of your Field Day operation.

Logging will be as good as the slowest laptop connected to the network. As of this posting only laptops running the last release of Windows 7 with 2GB RAM minimum or Windows 10 with 4GB RAM minimum and latest patches should be used as logging clients on the network. 

Guaranteed if someone brings an old Windows XP laptop they had in a closet since last Field Day it will introduce problems for logging with more than a half-dozen laptops. 

Only run services on the network necessary to support logging. Providing Internet access on your wireless network is only asking for trouble. Laptops that have not been updated prior to Field Day will see the Internet connection and look to start updating themselves with no consideration for available bandwidth. 

The wireless network should also be password protected since mobile phones are often set to look for open networks and try to find Internet connectivity through them as costs savings to users in their cell plans.

Network Design

Wireless routers. In following the network considerations mentioned, a stock Linksys WRT54GS wireless router with a pair of 7dBi antennas has served me well for many years as the anchor for a wireless network supporting up to eight logging laptops within a 75 foot radius of the wireless router.

Services. A flat network plan is followed with 192.168.73.0/24 used for the wireless (WPA2 password protected) and wired connections. DHCP services are providing assigning 192.168.73.128-252 to laptops. 

The Field Day server is setup with a static IP address of 192.168.73.100 and is not a client of DHCP services. In the the vein of keeping it simple, name services is not used so the server is always referenced by its IP address.

Pi Server

In using the software, the file share method for networking is proven reliable. Over the years I started with a Raspberry Pi 1 Model B+ and then a Raspberry Pi 2B as a server with a wired connection to the wireless router. The server is configured with a static IP address of 192.168.73.100 and runs two services.

The first service is Samba (Windows File Server.) A club account is created as a standard user and is used as the owner of a password-protected file share that hosts the log file.

The second service is Nginx web server. Why? To provide a self-service kiosk for those who need to setup their laptops for logging, info for operations on site, as well as a repository for registered and open-source software operators may need to setup their station for other modes. Nginx requires little resources and uses simple static web pages.

Lessons from the Field

Oh no... read the message .. then wait

Patience grasshopper. While there has been no loss of data by the servers, there have been issues born from lack of human patience. The software recognizes within a minute if the server is unavailable and will keep retrying until it is back online. 

But instead of waiting users panic, shutting off the software and restarting. When they do that they may
see no error but what has happened is they are disconnected from the network share and the software will start writing to a local MDB file with no warning. 

You end up with a new local file that needs to be added and reconciled with the network log file. when the server goes down, stations should do nothing and wait for the server to come back up and let the software do its thing.

Triage not Helpdesk. I make it abundantly clear that if someone asks me for help in getting their laptop working with the logging software and network that I will be focused on that task at the risk of disrupting other applications. Enough said so end-users know your laptops well.

All-in-one Server/Network. If you are comfortable with Linux and the Raspberry Pi you can reduce component count and have a Raspberry Pi 3 B+ or better do double-duty as server and wireless access point (WAP). 

As a WAP you disable onboard Bluetooth and WiFi and use an external higher-power WiFi device with external antenna. You will need to ensure you have adequate power to the Pi to support the external WiFi device.

Other Bits

Adding Time Services. This would be one more service I would consider adding to the server not just for logging but laptops that are running digital modes that require time synchronization (FT4/8.) 

Time would be sourced from an attached GPS dongle and available via NTP server process. Laptops would need to run a NTP client application to sync time with the server.

I want my Internet. If you insist. Go with a wired network to all laptops who are doing logging duty. Make as much of the network connectivity wired as possible. Internet connectivity should be via the WAN port on the WAP. 

If you doing an All-in-one server approach connect to the Internet via USB to a cell phone that can provide Internet service.

Building a Pi Server. A work-in-progress of how to build your own Field Day Network Pi server is available on GitHub.

73,

- Joe, NE2Z