The OT-2 communicates with the Opentrons App via standard HTTP and WebSockets over a network connection. The OT-2 can connect via two available networking interfaces:

  • WiFi
  • USB, via an internal USB-to-Ethernet adapter

Over both interfaces, the robot “advertises” itself to the Opentrons App via multicast DNS (mDNS, also known as Bonjour) so that the app can know which IP address to reach out to for a given robot. 

Firewall requirements

  • mDNS discovery: UDP on port 5353
  • Robot communication: TCP on port 31950

Wi-Fi requirements

The OT-2 can connect to WiFi networks with the following types of security:

WPA2 personal

The OT-2 supports WPA2 personal networks.

WPA2 with EAP / 802.1x (e.g. enterprise and eduroam networks)

The OT-2 supports WPA2 enterprise networks with the following authentication types:

  • EAP-TTLS with TLS
  • EAP-TTLS with MS-CHAP v2
  • EAP-TTLS with MD5
  • EAP-PEAP with MS-CHAP v2

Open (no security)

The OT-2 can connect to open networks, but we don't recommend it, because anyone will be able to access the robot.

The OT-2 does not support captive portal networks.

MAC addresses

Finding your OT-2's MAC addresses

Currently, to see an OT-2's wired and wireless MAC addresses, you need to be already connected to the OT-2 (over either a wired or wireless connection).

When a wrong MAC address might be displayed

On robot software versions up to v3.19.0, there is a known problem with wireless MAC addresses. When the OT-2 isn't connected to any wireless network, the wireless MAC address shown in the Opentrons App will be wrong.

To see the correct wireless MAC address:

  1. Connect the OT-2 to any wireless network.
  2. Close and reopen the Opentrons App.

Did this answer your question?