Mega Modem User Guide


The easy to use NCD Mega Modem allows the complete line of NCD Enterprise series sensors to communicate with application software over USB, WiFi, Bluetooth, or MQTT connections.  All sensors are fully encrypted using 128-bit AES encryption.  WiFi, Bluetooth and MQTT communication is also fully encrypted for your security.  To get started using the NCD Mega Modem, follow the steps outlined below.

Powering up the Mega Modem for the first time

Make sure your Gateway is in setup mode which is indicated by a flashing blue LED.  If the gateway is not in setup mode see Entering Setup Mode below under Troubleshooting.  Once it is in setup mode open the WiFi network preferences on your computer and scan for WiFi networks.  The Gateway should show up in the WiFi network scan as WiFi Micro Gateway. Select WiFi_Micro_Gateway.

When prompted for a password enter: NCDBeast

Initial Configuration

Once connected to the Mega Modem a browser window will appear on your screen.  If for some reason this browser window does not appear open your browser and enter the IP address press enter.

This browser interface allows for custom user configuration of the modem including USB connection settings, WiFi network connection settings, Bluetooth network connection settings, MQTT connection settings, and Soft AP settings.  Enter your settings as needed and then press Save Settings.

Settings Detail


  • Enabled Whether or not to connect to a WiFi network.
  • Network The SSID of the WiFi Network to connect to.
  • Password The required password for the WiFi Network.
  • DHCP Enabled If checked Obtain IP from network via DHCP or if not checked use static IP settings listed below.  Generally users opt for DHCP, all WiFi settings below are irrelevant if this box is checked.
  • Subnet Mask Network subnet mask.
  • DNS Primary Primary DNS server to use.
  • DNS Secondary Secondary DNS server to use.
  • Static IP Static IP address to use on connected network.

Soft AP

When the Mega Modem is in Setup mode it is in what we call Soft AP mode which means it serves as a WiFi access point and allows clients to connect directly to it like any other WiFi Network.  Soft AP mode can be used for daily use in some applications.  These settings modify that Soft AP network connection.

  • Soft AP SSID The displayed name of the MegaGateway in wifi scans.
  • Soft AP Password Required password for connecting to the MegaGateway as a WiFi Access Point.

UDP Broadcast

For discovery purposes the Mega Gateway will transmit a UDP broadcast to all network clients connected to the same WiFi Network.  This allows software to find the Mega Gateway for connection.

  • UDP Broadcast Broadcasts a UDP packet if checked, does not broadcast if not checked.
  • Link.SignalSwitch Broadcast Send UDP broadcasts to for remote internet discovery purposes.
  • UDP Discovery Name The display name of the Mega Modem in the UDP broadcast Packet.


The Mega modem supports software connection via the USB port.  It also communicates to wireless devices via an XBee socket.

  • Board Baud Rate The baud rate at which to communicate with the module installed in the XBee socket.
  • USB Baud Rate The baud rate at which to communicate with software clients connected via USB.


The Mega Modem supports software client connection via Bluetooth.  These settings dictate those Bluetooth connections as well as pairing.  This Bluetooth connection utilizes the Bluetooth connection profile Serial Port Profile(SPP) and may not be compatible with all Operating Systems.

  • Bluetooth Enabled Whether or not to enable Bluetooth connections.
  • Bluetooth Discovery Name Device name displayed in Bluetooth scans.
  • Bluetooth Pairing Code Required code for pairing with Mega Modem.


The Mega Modem supports software client connections via TCP sockets.  These settings dictate those TCP socket connections.  The Mega Modem acts as the TCP socket Server(it currently does not support connecting to other servers as a client).

  • TCP Server Enabled Whether or not to accept TCP socket connections.
  • TCP Listen Port The port on which to accept TCP socket connections.


The Mega Modem supports communication via MQTT.  The following settings dictate that connection.  The Mega Modem essentially works as a data tunnel between connected software and the XBee module.  Thus for the MQTT connection it utilizes just two topics one which it subscribes to(your software would write data to this topic) and one which it publishes to(your software would subscribe to this topic).  When data is received through the XBee module that data will be written to the Publish Topic.  When data is received through the Subscribe topic that data will be written to the XBee module.  Currently only Open and Basic Authentication(user name/password) is supported, however we may add TLS in the future.

  • MQTT Enabled Establish connection to an MQTT broker or not.
  • Host URL of the MQTT Broker.
  • Host Port The port on which the MQTT broker accepts connections.
  • Client ID The Client ID to use for MQTT connection to the Host.
  • Username The Basic Authentication Username to use for MQTT connection.
  • Password The Basic Authentication Username to use for MQTT connection.
  • Subscribe Topic MQTT topic to subscribe to.
  • Publish Topic MQTT topic to publish to.


Enter Setup Mode

  1. Remove the lid from the Modem Enclosure by first loosening the 4 Phillips head screws.
  2. Connect 12VDC to the Modem through the 2.1mm Barrel connector.
  3. Locate the red CFG button located on the Modem PCB.
  4. Press and hold the CFG button until the on board LED turns Blue.
  5. The Modem is now in setup mode and will appear as a WiFi Access Point which you can connect to from your computer, smart phone, or tablet.

Status LED color codes.

Flashing Green(GOOD)

A flashing Green LED indicates that the Gateway is in run mode and is ready for normal use.  It also indicates there is not an open TCP socket or Bluetooth connection to the board.  It however does not indicate whether or not a USB connection is made to the board.  If you are utilizing connection to the board via USB it is normal for the LED to flash green for the duration of use.

Solid Green(GOOD)

A solid Green LED indicates that a connection from software has been made to the modem either through a TCP socket or over Bluetooth.

Flashing Red(BAD)

A flashing Red LED indicates that connection to the stored WiFi network could not be achieved.  In this case it is recommended to put the Modem into setup mode as explained above and check the WiFi network settings.

Flashing Yellow

A yellow flashing LED indicates that the Modem is in the process of booting.  This should only happen on restart of the Modem.

Flashing Blue

A blue flashing LED indicates that the Modem is in setup or config mode so it should appear as a WiFi AP which you can connect to for configuration.  While in Setup Mode the modem will not function as it does in normal run mode.