Some projects only focus on safety in the third week of setup: the arm is mounted, gripper signals show the PLC has no spare I/O, the emergency-stop circuit does not match plant standard, and the EHS team asks for a risk review. The issue is usually not that the cobot is “unsafe.” It is that safety and I/O were never written into the quote scope.
Collaborative robots often need less fencing, but you still need written answers: Do people enter the work zone during normal operation? At what speed does each motion run? Who wires gripper and equipment signals? Who may restart after an emergency stop? This guide helps you define scope before you quote. It does not replace formal risk assessment or local regulations.
Four topics to align before you quote
1. Work zone boundary Floor marking, light curtain, area scanner, or a fixed station plus training so people do not enter. Note whether hands enter during changeover or loading.
2. Speed and people nearby Separate “transfer speed when no one is close” from “reduced speed or hold when someone is nearby.”
3. Emergency stop and reset Where buttons sit, whether the main contactor opens, how the cell interlocks with line e-stop, and who may restart after a stop.
4. Tool I/O scope Gripper, vacuum, vision OK, conveyor interlock: how many digital inputs and outputs (DI/DO), voltage, and who supplies valves and harnesses.
Assumptions that often cause trouble
“Collaborative means no risk assessment.” EHS may still require documentation before production. At minimum, prepare a short question list and a written boundary.
“I/O is included in the arm price.” Finding out during setup that the PLC must change adds cost and delay. List I/O as its own line on the quote.
“E-stop on the arm is enough.” If it does not match line e-stop logic, interlocks and reset become ongoing disputes. Align with the existing plant topology early.
“Safety quoted separately from the end effector.” Vacuum valves and gripper feedback directly affect wiring and cycle time. Set the tool path and I/O together → https://roooll.com/en/insights/guides/how-to-choose-cobot-end-effector
Procurement, EHS, and the integrator each keep a different version. After the contract is signed, versions drift. Send one scope page and your comparison link to everyone involved.
A 15-minute alignment: five questions
Put these in the meeting notes before you ask for a quote:
During normal operation, do people enter the robot work envelope? How often?
Who handles changeover and loading? Is a zone hold needed?
After e-stop, how is reset done? Who authorizes restart?
Which signals are needed at the tool (grip feedback, vacuum sense, OK/NG)?
Who builds the PLC or MES interface, and when is it due?
What to state clearly in the quote package
Usually include in the main quote or attachments: arm, control cabinet, teach pendant; stated DI/DO count; brief e-stop approach; draft tool I/O wiring sketch.
Often quoted separately or confirmed later: civil work or fencing changes, major PLC program work, third-party certification fees, clean or hazardous environments.
Fit with the rest of selection
Safety and I/O are not add-ons after signature. They belong with payload, reach, cycle time, and layout in pre-quote alignment. The common mistakes guide lists tool I/O and safety in its quick audit → https://roooll.com/en/insights/guides/common-cobot-selection-mistakes
Next step
End effector and vacuum I/O: https://roooll.com/en/insights/guides/how-to-choose-cobot-end-effector
Compare cabinet and I/O across tiers: https://roooll.com/en/selector/comparison
Have station video or electrical drawings? https://roooll.com/en/contact
