Festo SBS Vision Sensor — No Image or No Trigger

Festo · intermediate · 20 min

A Festo SBS/SBSi vision sensor that shows no live image or never inspects is usually stuck in the wrong trigger mode or unreachable on the network. Learn to switch between free-run and triggered capture in Vision Sensor Configuration Studio and fix the connection.

ℹ️ A Festo SBS that 'shows nothing' is almost always a trigger-mode setting: set to Trigger it waits for a hardware pulse; set to Continuous (free run) it images constantly. Pick the right one in Vision Sensor Configuration Studio for what you're doing.

The two tools

Festo SBS / SBSi vision sensors are set up with two pieces of software: the Vision Sensor Device Manager (finds sensors on the network and sets IP) and Vision Sensor Configuration Studio (builds the job — image acquisition, trigger, checks, outputs). Most "no image" or "it never inspects" cases are a trigger-mode setting or a network problem, so check those two first.

Get a live image: free run vs trigger

Under Job → Image Acquisition → Trigger mode in Configuration Studio you choose how the sensor captures:

Trigger — the sensor captures one image per external trigger pulse. If you're set to Trigger but no trigger signal is arriving, you'll see no new image and no inspection — it's waiting.
Continuous (free run) — the sensor images continuously without a trigger. This is the setting to use when you just want a live, updated image to set up or check focus/exposure.

So the fix for "no image while I'm setting it up" is to switch to free run / Continuous; the fix for "it images in setup but never inspects in production" is to confirm the external trigger is actually wired and pulsing when set to Trigger.

If the sensor isn't found on the network

If Configuration Studio / Device Manager can't see the sensor at all, it's an addressing problem: use the Device Manager to find the sensor and set its IP address so it shares the PC's subnet. Fix connectivity before trying to build or debug a job.

Step-by-step

Sensor not listed? Open Device Manager, find it, set its IP on the PC's subnet.
No live image during setup? In Configuration Studio set Job → Image Acquisition → Trigger mode = Continuous (free run).
Images in setup but never inspects? Set Trigger mode = Trigger and confirm the external trigger input is wired and actually pulsing (from the PLC/photoeye).
Tune exposure/focus and the checks on the live image, then switch back to Trigger for production.
Verify the output fires on a real part.

Never do this

Don't leave a production sensor in free run to "make sure it sees something" when the process needs synchronised, triggered captures — you'll inspect the wrong moment and pass or fail parts inconsistently. Use a proper external trigger tied to part presence.

Key points

Festo SBS/SBSi sensors use Vision Sensor Device Manager (network/IP) and Vision Sensor Configuration Studio (job/trigger/checks).
Trigger mode is set under Job → Image Acquisition → Trigger mode in Configuration Studio.
Trigger = one image per external pulse (no pulse = no image); Continuous/free run = images constantly, best for setup and focus.
No image in setup → switch to Continuous; images in setup but never inspects → set Trigger and confirm the external trigger is wired and pulsing.
Sensor not found on the network → use Device Manager to set its IP on the PC's subnet before building or debugging a job.

Codes and symptoms

No image (Trigger mode) — Waiting for a trigger: In Trigger mode the sensor captures one image per external pulse. No new image means no trigger is arriving — for setup switch to Continuous (free run).
Images but never inspects — Trigger not wired/pulsing: The job runs in setup but not in production because the external trigger isn't connected or pulsing. Wire the trigger from the PLC/photoeye and confirm it fires.
Sensor not found — Network/IP mismatch: Configuration Studio can't see the sensor. Use the Vision Sensor Device Manager to set the sensor's IP on the same subnet as the PC.