Universal Robots Nodes

Read RTDE data and the robot's status, and play, pause, stop or load programs on Universal Robots cobots from a pipeline.

Reads

RTDE sample · Dashboard status

Commands

Only in remote control

Limits

A command is never retried automatically

Use Universal Robots cobots (CB3, e-Series, URSim) in pipelines. Each function authored on a Universal Robots connection is available as a matching node in the Pipeline Designer.

For connection setup, RTDE variables and the safety rules for commands, see the Universal Robots connection guide.

For the event-driven trigger, see the Universal Robots Trigger node. It starts a pipeline with an RTDE sample once per publish interval (the Monitor RTDE function, trigger.universalrobots); its result is read as $trigger.result.values, $trigger.result.labels and so on.

Configuration Quick Reference

Field	What you choose	Details
Parameters	Connection, Function, Function Parameters, Timeout Override	Select the Universal Robots connection, pick a function, bind parameters with expression support, and optionally override the timeout.
Settings	Description, Timeout (seconds), Retry on Timeout, Retry on Fail, On Error	Node description, maximum execution time, retry behaviour and error strategy. All execution settings default to pipeline-level values.

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Universal Robots Read RTDE Node

Supported Function Types:

Node	Function	Purpose	Common Use Cases
Universal Robots Read RTDE (connected.universalrobots.read)	universalrobots.read	One RTDE sample of the listed output variables	Joint positions and TCP pose before a quality check; robot and safety mode before a decision

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Universal Robots connection profile to use
Function	Selection	Yes	A universalrobots.read function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema. See Read RTDE.
Timeout Override	Number (seconds)	No	Override the default function timeout

Input

The node receives the output of the previous node as input.

Output Structure

{
  "result": {
    "values": { "actual_q": [0, -1.5708, 1.5708, -1.5708, -1.5708, 0], "robot_mode": 7 },
    "labels": { "robot_mode": "RUNNING" },
    "controllerTime": 12345.678,
    "quality": "good",
    "serverTimestamp": "2026-10-20T10:14:03.221Z"
  }
}

Key	Meaning
result.values	One entry per RTDE variable asked for, by name: numbers, booleans, or arrays for vectors (6 joints, 6-D poses, 3-D vectors)
result.labels	Readable names for the mode variables asked for (robot_mode, safety_mode, safety_status, runtime_state), e.g. RUNNING, PROTECTIVE_STOP, PLAYING; UNKNOWN for a code this release does not know
result.controllerTime	The controller's clock, in seconds since it started
result.quality	good: the robot sent the sample
result.serverTimestamp	When MaestroHub received the sample, UTC

Read a joint with $node["Read Joints"].result.values.actual_q[0] and a mode with $node["Read Joints"].result.labels.robot_mode.

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Universal Robots Read Status Node

Supported Function Types:

Node	Function	Purpose	Common Use Cases
Universal Robots Read Status (connected.universalrobots.status)	universalrobots.status	Robot mode, safety status and program state from the Dashboard server	Checking the robot before a program command; shift reports

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Universal Robots connection profile to use
Function	Selection	Yes	A universalrobots.status function from the selected connection
Timeout Override	Number (seconds)	No	Override the default function timeout

Input

The node receives the output of the previous node as input.

Output Structure

{
  "result": {
    "robotMode": "RUNNING",
    "safetyStatus": "NORMAL",
    "programState": "PLAYING",
    "programName": "pick.urp",
    "loadedProgram": "/programs/pick.urp",
    "programRunning": true,
    "polyscopeVersion": "5.25.2.130406",
    "remoteControl": true,
    "unsupported": []
  }
}

Key	Meaning
result.robotMode	NO_CONTROLLER, DISCONNECTED, CONFIRM_SAFETY, BOOTING, POWER_OFF, POWER_ON, IDLE, BACKDRIVE or RUNNING
result.safetyStatus	NORMAL, REDUCED, PROTECTIVE_STOP, SAFEGUARD_STOP, … (the safety mode on older controllers)
result.programState	STOPPED, PLAYING or PAUSED
result.programName	The program the state refers to, as the robot names it (<unnamed> when none)
result.loadedProgram	The loaded program's path, or null when none is loaded
result.programRunning	Whether a program is running
result.polyscopeVersion	The PolyScope software version
result.remoteControl	Whether the robot accepts program commands from the network; null on controllers without local/remote control
result.unsupported	The questions this controller did not understand; their fields are null

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Universal Robots Program Command Node

Supported Function Types:

Node	Function	Purpose	Common Use Cases
Universal Robots Program Command (connected.universalrobots.programCommand)	universalrobots.programCommand	Play, pause, stop or load a program	Order-driven program changes, pausing on an upstream fault

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Universal Robots connection profile to use
Function	Selection	Yes	A universalrobots.programCommand function from the selected connection
Function Parameters	Dynamic	Varies	The program to load can be a ((parameter)). See Program Command.
Timeout Override	Number (seconds)	No	Override the default function timeout

Input

The node receives the output of the previous node as input.

Playing a program moves the robot; a command is never sent twice automatically

The node first asks the robot whether it is in Remote Control and sends nothing when it is not. If the command fails after it may have reached the robot (no reply, a dropped link, an unknown answer), the node fails with outcome unknown and is not retried, even with Retry on Fail or a ForEach retry configured. Read the robot's status before running it again. A command the robot refused fails as refused and is not retried either.

A command is also refused in a run started by a late (replayed) value, unless the node allows late input.

Output Structure

{
  "result": {
    "command": "load",
    "program": "pick.urp",
    "reply": "Loading program: /programs/pick.urp",
    "accepted": true,
    "remoteControl": "true"
  }
}

Key	Meaning
result.command	The command sent: play, pause, stop or load
result.program	load only: the program path as given
result.reply	The Dashboard server's reply, word for word
result.accepted	The robot accepted the command; always true on a success
result.remoteControl	"true" when the robot confirmed remote control first; "unsupported" on a controller without local/remote control

Safety First

Check the robot with a Read Status node and validate the request in a Condition node before a pipeline plays a program.

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Errors

Error	Meaning	Retried by the node settings?
the robot is in local control …	The robot is not in Remote Control; nothing was sent	No
the robot refused …	The robot answered with a refusal (Failed to execute, File not found, …)	No: the result is permanent
outcome unknown: …	A command failed after it may have reached the robot	Never, whatever the retry settings
the robot does not know the RTDE output variable(s) …	A variable name is wrong	No
not connected	The connection is down	Yes

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Settings Tab

All Universal Robots node types share the same Settings tab:

Setting	Type	Default	Description
Description	Text	-	Optional description displayed on the node
Timeout (seconds)	Number	Pipeline default	Maximum time the node may run before timing out
Retry on Timeout	Toggle	Pipeline default	Automatically retry the node if it times out
Retry on Fail	Toggle	Pipeline default	Automatically retry the node if it fails
On Error	Selection	Pipeline default	Error strategy: Pipeline Default, Stop Pipeline or Continue Execution

The retry settings never re-send a Program Command whose outcome is unknown, and do not retry a request the robot refused (see Errors).