Safety I/O
Safety I/Os are used to set up additional safety I/O functions, such as additional emergency stop functions or safety functions than can be configured in the activation rules.
The safety connections are described below and their proper wiring is shown. Follow the specifications for all digital I/Os as listed under Specifications for all digital I/Os. Safety devices must be installed in accordance with the safety notices and the risk assessment, as described in Safety. There are two types of safety inputs:
- Robot emergency stop only for emergency stop devices
- Four pairs of secure inputs for triggering activation rules for configurable safety functions
The functional differences are shown in the following table:
| System | Emergency stop | Configurable safety functions |
|---|---|---|
| Robot stops movement | Yes | Yes (monitored standstill) |
| Program execution | Break | Break |
| Drive power | Off | On, but turns off if the standstill is violated |
| Reset | Manual | Depending on the configuration |
| Frequency of use | Frequently | Every cycle to rarely |
| Stop category (IEC 60204-1) | 1 | 1, 2 |
| Performance Level | PLd | PLd |
Hazards caused by uncontrolled robot movements
The installation of the robotic system must comply with the specifications described. Failure to follow these instructions may result in uncontrolled robot movements and serious injury or death.
► Install the robot system according to the specifications described.
► Checked the safety functions before commissioning the robot.
► Check safety functions regularly.
► Turn off the robot system before disconnecting or connecting any cables.
Hazards caused by uncontrolled robot movements
Transmitting safety signals from the PLC to non-safety-rated hardware reduces the safety level of the corresponding function, which can result in uncontrolled robot movements and serious injuries to people.
► Safety signals from the PLC must be transmitted to safe hardware.