# Firmware Lifecycle
Before OTA make sure to go through the list below.
- Make sure you have physical access to the device before starting the update process.
- Do not power off the device during the firmware update.
- If Site has Enapter Gateway it needs to be updated to version 1.8.9 or higher.
- Remove the Dryer Control Network (DCN) before updating the firmware (no need since 3.3.0).
- Electrolysers connected to DCN/IDCN should be version 1.10.0 or higher, otherwise monitoring and control from Electrolyser Web GUI or Modbus TCP interface won't work.
# Change Log
# New Features
- Added Air Regeneration Mode.
- Added Warning
WS_01: Air Regeneration is on. Don't supply hydrogen to the dryer and ensure depressurization line is open.
# Compatibility Matrix
Please carefully check the compatibility matrix for the 3.9.1 firmware version with the previous version.
- C - fully compatible;
- NC - not compatible;
- PC - party compatible, check additional notes.
# Functional Depreciation Statements
# Modbus Compatibility
- Begin with firmware version 3.6.0 Dryer input registers are deprecated, holding registers should be used instead.
# Known Bugs List
The list below contains the most important problems in the firmware and their solutions.
DCN may assign an IP address to devices (computers, mobiles) connected to Wi-Fi AP associated with DCN enabled Enapter devices.
- Delete the DCN from the Enapter Mobile App and create it one more time.
- If it is possible try to separate the DCN from your main network environment by connecting the DCN to another WiFi AP, no need to separate one DCN from another.