How to set up a Festo vacuum sensor (SPAE, part 8001443) for suction cup feedback

thijs · September 2, 2026, 12:15am

Based on contributions by JeroenDouw.

A vacuum sensor gives an analog feedback signal proportional to vacuum strength, so you can confirm a suction cup actually has a grip before a robot moves. This covers wiring a Festo SPAE vacuum sensor (part 8001443) and reading it from a UR robot.

What you need

Festo vacuum sensor SPAE, part number 8001443
A vacuum generator and suction cup circuit (see How to choose and use suction cups for picking up objects for what else you need to build one)
A free analog input on the robot/PLC
Python with the ur_rtde package installed, if reading the value from a PC (pip install ur_rtde)

Steps

1. Wire the sensor

Wire the sensor as shown below, and place it in series with the vacuum generator so it measures the actual vacuum being pulled, not just line pressure.

2. Wire the sensor into the pneumatic/electrical circuit

Connect the sensor’s signal wire to an analog input on your PLC or robot controller. This lets the analog vacuum value be read by the robot’s I/O.

3. Read the value in code

To read the analog value from Python using the ur_rtde library:

from rtde_receive import RTDEReceiveInterface

rtde_r = RTDEReceiveInterface("<robot IP>")
value = rtde_r.getActualAnalogInput0()  # replace 0 with the AI number the sensor is connected to

Check: the original source used a placeholder call (robot.getAnalogInput0()) without specifying the library. The code above assumes you’re using ur_rtde’s RTDEReceiveInterface, whose actual method is getActualAnalogInput0()/getActualAnalogInput1(). If you’re reading the value from a PLC instead, use that PLC’s analog-input read function.

Reference

SPAE operating instructions (PDF)