News

The Stage Robot Company Introduces DMX Tern, A DMX Terminator That Monitors The Fixtures On Its Line

By PR/Agency User Oct 18, 2026 9:33am

The Stage Robot Company, a developer of theatrical technology, today introduced the DMX Tern, a 5-pin DMX terminator that watches the health of every RDM-capable fixture on its line. It also introduced DMXTern+, a connected version that sends push notifications when a fixture reports a fault. Both products are available now.

Like any DMX terminator, the DMX Tern plugs into the last fixture on a DMX line and provides 120 Ω termination. Unlike a standard terminator, it also polls every RDM responder on the line for queued status messages (ANSI E1.20 QUEUED_MESSAGE) and reports what it finds through a single LED.

Green: DMX is present and no fixture has reported a problem.
Yellow: at least one fixture has reported a STATUS_WARNING.
Red: at least one fixture has reported a STATUS_ERROR.
Off: no DMX is present. The company refers to this state as resting.

The DMX Tern needs no power supply, configuration or software. It draws its operating power from the DMX line itself.

"Every DMX line ends somewhere," said Alan Smithee, founder and chief executive officer of The Stage Robot Company. "In 25 years in the entertainment industry, I have watched a great many of them end. Most of them ended without anyone knowing anything. I did not think that was acceptable, and I said so at the time. Today we are doing something about it."

A Terminator That Listens

"For forty years, the terminator has been a passive device," said Marko Dragic, chief technology officer of The Stage Robot Company. "It sat at the end of the line and absorbed whatever arrived. We asked whether it had to be passive. It turns out it does not. The Tern listens, and it is very good at listening. I have worked with sensitive monitoring equipment in environments that were far less forgiving than a theatre, and I am comfortable saying this is the most attentive device I have ever built."

The Pinewood Regional Playhouse installed DMX Tern units on all 12 of its DMX lines during beta testing.

"The first night we installed it, it turned red," said Owen Tillery, master electrician at the Pinewood Regional Playhouse. "We checked every fixture on that line and found nothing wrong. The next morning, a moving light on that line failed. We now have one on every universe. Nobody on the crew unplugs them. Nobody has discussed this. It's just understood."

DMXTern+: the terminator, connected

DMXTern+ does everything the DMX Tern does. It also joins the venue's Wi-Fi network and reports to TernCloud, The Stage Robot Company's monitoring service. When a fixture on the line reports a warning or an error, or the DMX stream itself drops out or falls outside specification, DMXTern+ sends a push notification to every subscribed device on iOS, Android and supported smartwatches.

Alerts can be shared with an unlimited number of crew members, and with their families. TernCloud keeps a full fault history for every fixture it has ever observed. The history is retained indefinitely.

"Before DMXTern+, I found out a light was broken when the director found out a light was broken," said Tillery. "Now I find out at 3 a.m., wherever I am. My partner finds out too. We've adjusted."

Named for the Arctic Tern

The DMX Tern is named for the Arctic tern (Sterna paradisaea). The bird makes the longest known migration of any animal, about 44,000 miles each year from pole to pole. It experiences more daylight than any other creature on Earth.

"The tern is vigilant, it travels great distances, and it is rarely in the dark," said Smithee. "We felt those were the right values for a terminator."

Key specifications

DMX Tern

5-pin XLR male, 120 Ω termination
ANSI E1.20 RDM: polls QUEUED_MESSAGE, reports STATUS_WARNING and STATUS_ERROR
One tri-color status LED (green / yellow / red / off)
Parasitically powered from the DMX line
No setup required

DMXTern+

Everything in DMX Tern
Wi-Fi 802.11 b/g/n/ax
Monitors DMX stream health: dropouts, refresh rate, break timing
Push alerts via TernCloud (iOS, Android, smartwatch)
USB-C auxiliary power for the Wi-Fi radio

Compatible with any RDM-capable fixture that supports QUEUED_MESSAGE. Fixtures that do not support RDM are assumed to be fine.

Pricing and Availability

The DMX Tern is available now from authorized StageRobot dealers at a suggested retail price of USD $79. It is also sold as the DMX Tern Colony, a 10-pack, for USD $690. DMXTern+ is available now for USD $149 and requires a TernCloud Flock subscription at USD $9 per month. Each Flock subscription supports an unlimited number of DMXTern+ units, alerts and recipients.

About The Stage Robot Company

The Stage Robot Company builds interesting theatrical technology for lighting, video and control. Its products include Unicore sACN, the DMX Tern and DMXTern+ smart terminators, and PVA, a production virtualization system. The company is headquartered in a building in Los Angeles. The Stage Robot Company does not manufacture robots. For more information, visit stagerobot.com.

Media contact Press Office, The Stage Robot Company [email protected]

StageRobot, Unicore, DMX Tern, DMXTern+, TernCloud and PVA are trademarks of The Stage Robot Company. All other trademarks are the property of their respective owners.

Stage Robot Company Gear Live Design Online Homepage News