In a PLC program, multiple safety interlocks are arranged in what configuration?

In a PLC program, multiple safety interlocks are typically arranged in a series configuration. This arrangement requires all interlocks to be satisfied or closed before the system can operate. When interlocks are in series, each condition must be true for the system to proceed, which ensures maximum safety. If any one of the safety interlocks is open or not met, it will prevent the operation of the machinery or process, thereby protecting operators and equipment from potential hazards.

This configuration is critical in applications where safety is paramount, as it guarantees that all necessary safety conditions are verified before activating any potentially dangerous operations. For example, if a machine has multiple safety gates or emergency stops, they are best wired in series so that the opening of any one will trigger a shutdown of the entire system. This highlights the importance of circuit configurations in ensuring operational safety within programmed control systems.