Network Issues - Troubleshooting Guide

Network problems can make your robot uncontrollable or unresponsive. This guide helps you diagnose and fix network issues quickly.

Quick Check (1 minute)

1 Check Physical Connections

Look for:

• Ethernet cable connected to RoboRIO.
• Ethernet cable connected to radio.
• Radio powered on (solid orange/green lights)
• Computer connected to robot network.

What should you see:

• ✅ RoboRIO: Orange link light (connected)
• ✅ Radio: Solid orange/green lights.
• ✅ Computer: Connected to robot-XXXX network.

2 Check Driver Station

Look at these indicators:

• Communications: Green (good), Red (bad), Orange (searching)
• Robot Code: Green (running), Red (not running)
• Joysticks: Shows controller connection status.

What you want:

• ✅ Communications: Green.
• ✅ Robot Code: Green.
• ✅ Joysticks: Your controller listed.

3 Check Team Number

Verify team number matches:

• Driver Station team number: XX-XXX.
• RoboRIO team number: Same as Driver Station.
• Radio team number: Same as Driver Station.

Mismatch causes: Connection failures, wrong robot controlled

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Common Problems and Solutions

Problem 1: “Communications Lost” (Red)

Symptoms:

• Driver Station shows “Communications: Red”.
• Robot becomes unresponsive.
• Code stops running.
• Can’t drive or control robot.

Causes:

1. Radio Not Powered or Connected

Fix: Check radio power and connections

• Check 12V power to radio (from PDP or VRM)
• Verify ethernet cable from RoboRIO to radio.
• Check radio lights (should be solid, not blinking)

2. Wrong Network

Fix: Connect to correct network

• Computer should be connected to robot-XXXX-XX-XXX
• NOT your home/school WiFi.
• NOT the radio’s setup network (192.168.XX.X)

3. Firewall Blocking

Fix: Temporarily disable firewall

• Windows Firewall can block robot communication.
• Disable firewall during competition.
• Add exceptions for FRC programs.

4. IP Address Conflicts

Fix: Check for duplicate IP addresses

• Only one device should have each IP.
• RoboRIO: 10.TE.AM.2.
• Radio: 10.TE.AM.1.
• Computer: DHCP from radio.

Problem 2: “Robot Code” Red (Not Running)

Symptoms:

• Driver Station shows “Robot Code: Red”.
• Code deployed but not running.
• Robot does nothing even with comms green.

Causes:

1. Code Crashed on Startup

Fix: Check RioLog for errors

• Open RioLog
• Look for red error messages.
• Common crashes: NullPointerException, missing libraries.
• Fix crash and redeploy.

2. Wrong Main Class

Fix: Verify Main class in build.gradle

// Should match your main robot class
def mainClassName = "frc.robot.Main"

3. Deployed to Wrong Location

Fix: Ensure code is deployed to RoboRIO

• Run ./gradlew deploy
• Watch for “BUILD SUCCESSFUL”.
• Check RioLog shows “Robot code starting”.

Problem 3: Intermittent Connection Drops

Symptoms:

• Robot works, then loses connection randomly.
• Driver Station shows orange then red.
• Connection comes back after a few seconds.

Causes:

1. Bad Ethernet Cable

Fix: Replace ethernet cable

• Try different cable.
• Check for damage.
• Use shielded cable for long runs.

2. Radio Overheating

Fix: Improve radio ventilation

• Radio can overheat in enclosed spaces.
• Add cooling fan.
• Improve airflow around radio.

3. Power Issues

Fix: Check power connections

• Verify 12V power supply is stable.
• Check PDP/VRM connections.
• Measure voltage at radio (should be ~12V)

Problem 4. Joysticks Not Detected

Symptoms:

• Driver Station shows “Joysticks: None”.
• Can’t drive robot.
• Controller doesn’t work.

Causes:

1. USB Controller Disconnected

Fix: Reconnect controller

• Unplug and replug controller.
• Try different USB port.
• Replace controller if damaged.

2. Driver Station Not Seeing Controller

Fix: Refresh USB devices

• Click “USB Devices” tab in Driver Station.
• Click “Refresh”.
• Verify controller appears.

3. Wrong USB Port

Fix: Use different USB port

• Some USB ports don’t work well.
• Try USB 2.0 port, not USB 3.0.
• Try port directly on computer, not hub.

Problem 5. Can’t Connect to Radio Web Interface

Symptoms:

• Can’t access radio configuration page.
• http://192.168.XX.X won’t load.
• Can’t configure radio settings.

Causes:

1. Connected to Wrong Network

Fix: Connect to robot network

• Must be connected to robot-XXXX-XX-XXX
• NOT 192.168.XX.X (setup network)
• NOT your home network.

2. Wrong IP Address

Fix: Use correct radio IP

• OM5P radio: http://192.168.XX.X (XX = team number last 2 digits)
• Old radio: http://10.TE.AM.1
• Check radio label for actual IP.

3. Browser Issues

Fix: Try different browser or clear cache

• Try Chrome or Firefox.
• Clear browser cache.
• Try incognito/private mode.

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Network Setup Verification

Step 1: Verify Network Configuration

Check RoboRIO network settings:

# In RioLog, check network configuration
# Should show:
# IP: 10.TE.AM.2 (static from radio)
# Netmask: 255.255.255.0
# Gateway: 10.TE.AM.1 (radio)

Check radio configuration:

Login to radio at http://192.168.XX.X
Verify:
- Team number correct
- Bridge mode enabled
- DHCP enabled

Step 2: Test Connectivity

Ping test:

# From computer, ping RoboRIO
ping 10.TE.AM.2

# Should get replies
# If "Request timeout", network not working

Trace route:

# See where connection fails
tracert 10.TE.AM.2

# Should go: Computer -> Radio -> RoboRIO

Step 3: Check NetworkTables Connection

Verify NetworkTables connected:

• Open OutlineViewer or SmartDashboard.
• Look for /SmartDashboard folder.
• Check that you can add values.
• Verify values appear on both sides.

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Competition Network Issues

Problem: Works at Home, Not at Competition

Common competition network differences:

1. Field Network Interference

Fix: Use provided 5GHz USB WiFi adapter

• Competition fields provide WiFi adapter.
• Connect it to Driver Station computer.
• It’s preconfigured for field network.

2. Wrong Team Number

Fix: Ensure team number matches competition assignment

• Official FRC event team number.
• Must match what you registered with.
• Check FMS for correct number.

3. Cable Management

Fix: Secure all network cables

• Cable management prevents disconnects.
• Use zip ties and strain relief.
• Protect cables from robot movement.

Problem: FMS (Field Management System) Issues

Common FMS problems:

1. FMS Can’t Connect to Robot

Fix: Check team number, network settings, radio power

• Verify team number in Driver Station.
• Check radio is connected and powered.
• Ensure RoboRIO is powered and connected.

2. DS Errors on FMS

Fix: Check Driver Station logs

• Look for specific error messages.
• Address common errors:
  • “Team number mismatch”.
  • “Radio not connected”.
  • “Bandwidth too high”.

3. Robot Radio Not Responding

Fix: Power cycle radio and RoboRIO

• Turn off robot.
• Unplug radio power.
• Wait 10 seconds.
• Reconnect and power back on.

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Network Best Practices

Before Competition

Setup:

• ✅ Use high-quality ethernet cables.
• ✅ Label all network cables.
• ✅ Test connection with radio.
• ✅ Practice reconnection quickly.
• ✅ Document network settings.

Testing:

• ✅ Test with Driver Station.
• ✅ Verify all joysticks work.
• ✅ Test connection drops.
• ✅ Practice reconnecting under pressure.

During Competition

Monitoring:

• ✅ Check Communications status.
• ✅ Watch for red indicators.
• ✅ Monitor CAN bus utilization.
• ✅ Note any network issues.

Quick Recovery:

• ✅ Have spare ethernet cables.
• ✅ Know how to power cycle quickly.
• ✅ Practice reconnection procedures.
• ✅ Stay calm under pressure.

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Quick Fixes

Fix 1: Power Cycle Robot

1. Disable robot in Driver Station.
2. Turn off main robot power.
3. Wait 10 seconds.
4. Turn robot back on.
5. Enable in Driver Station.

Fix 2: Reconnect Network

1. Unplug ethernet from computer.
2. Wait 5 seconds.
3. Reconnect ethernet.
4. Wait for connection to re-establish.
5. Verify Communications green.

Fix 3: Restart Driver Station

1. Close Driver Station completely.
2. Wait 5 seconds.
3. Reopen Driver Station.
4. Reconnect joysticks.
5. Enable robot

Fix 4: Check Radio Configuration

1. Connect to robot network.
2. Login to radio at http://192.168.XX.X.
3. Verify team number.
4. Check bridge mode enabled.
5. Save and reboot radio.

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Prevention Tips

Network Setup

Do:

• ✅ Use velcro or zip ties for cables.
• ✅ Label both ends of each cable.
• ✅ Route cables away from sharp edges.
• ✅ Use right-angle connectors where needed.
• ✅ Test connection regularly.

Don’t:

• ❌ Run cables near motor power wires.
• ❌ Leave cables loose to vibrate out.
• ❌ Use damaged cables.
• ❌ Ignore intermittent connection issues.
• ❌ Forget to test before competition.

Competition Preparation

Essential Items:

• Spare ethernet cables (2-3)
• USB WiFi adapter (provided at event)
• Network configuration sheet.
• Contact info for FTAs (Field Technical Advisors)
• Backup plan for network failures.

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Diagnostic Commands

Windows Network Diagnostics

# Check network connection
ping 10.TE.AM.2

# Trace route to robot
tracert 10.TE.AM.2

# Check DNS resolution
nslookup robot-XXXX-XX-XXX.local

# Check network interfaces
ipconfig

Linux/Mac Network Diagnostics

# Check network connection
ping 10.TE.AM.2

# Trace route to robot
traceroute 10.TE.AM.2

# Check network interfaces
ifconfig

# Check routing table
netstat -rn

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Advanced Troubleshooting

Capture Network Traffic

Use Wireshark to analyze network issues:

# Install Wireshark
# Start capture on robot network interface
# Filter for:
# - DNS traffic
# - NetworkTables updates
# - Disconnection events

Monitor NetworkTables

Check for NetworkTables spam:

// Add to robotInit()
NetworkTableInstance.getDefault().addEntryListener(event -> {
    System.out.println("NT update: " + event.key.getFullName());
});

What to look for:

• Updates every 20ms = OK (periodic)
• Updates every 1ms = Too frequent (problem!)
• No updates = Connection issue.

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When to Get Help

At Competition

Field Technical Assistant (FTA):

• Ask FTA for help with field network.
• They can diagnose FMS issues.
• They have tools to check field network.

Robot Inspector:

• Can help with basic network setup.
• Can check team number configuration.
• Can verify robot connections.

Never Alone

Network issues are common:

• Every team experiences them.
• FTAs are there to help.
• Other teams can assist.
• Don’t panic, work systematically.

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Network Checklist

Before Leaving for Competition

• Ethernet cables tested and labeled.
• Radio configured with correct team number.
• Driver Station team number set.
• All joystools tested.
• Connection tested with robot.
• Spare cables packed.
• Network configuration printed.

At Competition

• Connect to field WiFi adapter.
• Verify team number in Driver Station.
• Test connection to robot.
• Test all joysticks.
• Run through robot inspection.
• Practice reconnection procedures.

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Related Guides

• CAN Bus Issues
• Driver Station Setup
• Radio Configuration
• Competition Prep

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Remember: Good network practices prevent most issues. Test regularly and have backup plans for competition!

Still having network issues? Ask the community - describe your setup and symptoms!