Handling Epson U220 Printer going offline

🖨️ Epson U220 / U220II “Offline” Issue — 
Understanding and Fixing the Rare Standby Mode Condition

A small number of venues using Epson U220 or U220II printers with the EO4 network interface board may experience a situation where the printer appears offline in NX, even though it’s actually powered on and ready.

This condition is extremely rare — occurring in fewer than one in a million printers — but Epson has identified the cause and provided both an immediate workaround and a forthcoming firmware solution.

⚠️ The Issue

In some network environments, the printer may appear offline to the POS when it is actually still connected and waiting for data. Epson has reported networks with Netgear & Ubiquiti Networks "UniFi" equipment have been seen to trigger this event.

What Happens:

1. The printer is online and functioning normally. 
2. It enters Standby Mode, which is designed to conserve power while remaining ready for network communication. 
3. In certain cases, the network router or switch stops sending data to the printer after it enters standby. 
4. NX (and other POS systems) interpret this as the printer being offline, even though the printer itself never truly disconnected.

When this happens, printing stops temporarily until the printer is manually woken or restarted.

🌏 Background and Cause

Epson engineers in Japan successfully recreated this behavior under specific conditions and identified the root cause.

The combination of:

• Standby Mode 
• Energy Efficient Ethernet (EEE) 
  and certain router configurations can cause the printer to become unreachable even though it remains active on the network.

The network hardware essentially stops “seeing” the printer after a period of inactivity.

✅ The Recommended Fix (Workaround)

Until Epson’s updated firmware is rolled out, the current solution is simple and effective:

Disable the following printer settings:

• Standby Mode 
• Energy Efficient Ethernet (EEE)

Once these are turned off, the printer will remain consistently visible and available on the network, eliminating the offline detection issue.

Steps Summary:

• Access the printer’s configuration utility or web interface. 
• Navigate to Network Settings → Power Management. 
• Set Standby Mode → Off 
• Set Energy Efficient Ethernet → Off 
• Save settings and restart the printer.

🧠 Tip: If you are unsure how to access your printer’s configuration utility, refer to Epson’s support documentation for your specific model (U220 or U220II with EO4 board).

🔧 Firmware Update Coming Soon

Epson has confirmed that a firmware update will soon be available for newer units to permanently resolve this behavior.

This update:

• Adjusts how standby and network activity interact on the EO4 board. 
• Prevents the printer from being misinterpreted as offline in certain network environments.

For existing printers already in operation, the workaround above is sufficient to maintain normal operation until the updated firmware becomes available.

💬 Summary

🧩 Additional Notes

• The issue has only been reported a few times worldwide. 
• The issue appears to impact applications using the official Epson SDK. 
  • Applications that are sending requests directly to the printers do not appear to be impacted.
• Printers with built-in Ethernet interfaces (i.e. M30ii) are not impacted.
• Disabling power-saving features will not impact printer performance or reliability.

🆘 Need Help?

If you need assistance applying this fix or adjusting your printer’s settings, please contact NX Support or your Epson representative.

Turning off the two power management options will ensure continuous, stable communication between NX and your Epson U220 printer.