Rockwell Automation 440G-EMAS, Руководство пользователя, Страница: 15 / 44

Rockwell Automation Publication 440G-UM003A-EN-P - February 2020 15
Project Planning Chapter 3
Electrical Control
Integration
Switch-on commands that put the machine in a dangerous state can only be
activated when the protective device is closed. When the machine goes into a
dangerous state, a stop command must be triggered if the protective device is
opened. Depending on the safety concept, a safety relay or a safety controller
analyzes the signal.
The control that is connected and all devices responsible for safety must comply
with the required Performance Level and the required category (for example,
according to ISO 13849-1).
OSSDs
Safety switches with local inputs and outputs can be directly integrated into the
machine controller.
• The output signals from an OSSD pair must not be connected to each
other.
• In the machine controller, both signals from an OSSD pair must be
processed separately.
Figure 4 - Dual-channel and isolated connection of OSSD 1 and OSSD 2
• The machine must switch to the safe state at any time if at least one OSSD
in an OSSD pair switches to the OFF state.
• Prevent the formation of a potential difference between the load and the
protective device. If you connect loads to the OSSDs (safety outputs) that
then also switch if controlled with negative voltage (for example,
electromechanical contactor without reverse polarity protection diode),
you must connect the 0V connections of these loads and the connections
of the corresponding protective device individually and directly to the
same 0V terminal strip. If there is a fault, this way verifies that there can be
no potential difference between the 0V connections of the loads and the
connections of the corresponding protective device.
ATTENTION: Hazard due to lack of effectiveness of the protective device.
If non-compliant, it is possible that the dangerous state of the machine may not be
stopped or not stopped in a timely manner.
• Make sure that the following control and electrical requirements are met so the
protective function can be fulfilled.