AAP3798102-00037 DCS系统 PLC模块 伺服控制

AAP3798102-00037 DCS系统 PLC模块 伺服控制

AAP3798102-00037 DCS系统 PLC模块 伺服控制

这些早期控制设计的基础是主控继电器。通过这种电路设计，停止和启动整个系统的方法被绑定到单个电路。

随着电路变得越来越复杂，元件安全成为算法的一部分，因此电路中加入了电机过载等因素。操作员安全开始进入电路设计，保持接触式紧急停止开关成为主流。当时的紧急停止是一个单一的接触，作为一种保持电路关闭的手段，硬件供应商推出了一种附加设备，允许将锁插入紧急停止按钮周围的支架，以防止它被拔出。结果，主控制电路可能被禁用，直到锁被移除。安全电路的演变已经开始。

当然，这个基地是一个中继站。一个继电器提供一个安全的方法来降低设备的功率应该比普通继电器更坚固。一个叫做“力导”的术语就这样产生了。这些继电器以这样一种方式构造，以确保只有一个开状态和一个关状态。

其他制造商提出，如果一个继电器是安全的，两个会更安全。安全电路发展到使用两个串联继电器作为一种手段，以确保其中一个继电器的故障会导致整个电路的故障。

正如任何进化一样，在发展中的安全世界里也有旁门左道。大约在双重安全电路出现的时候，安全装置的双重电路的概念出现了。这一思考过程源于这样一种理念，即如果驱动两个继电器的一个电路是安全的，那么驱动这两个继电器的两个电路都需要是完整的，这将更加安全。

AAP3798102-00037 DCS系统 PLC模块 伺服控制

The basis of these early control designs was the master relay. With this circuit design, the method of stopping and starting the entire system is tied to a single circuit.

As circuits become more complex, component safety becomes part of the algorithm, so factors such as motor overload are added to the circuit. Operator safety began to enter circuit design, and the hold contact emergency stop switch became mainstream. The emergency stop at the time was a single contact, and as a means of keeping the circuit closed, hardware vendors introduced an add-on device that allowed the lock to be inserted into the bracket around the emergency stop button to prevent it from being pulled out. As a result, the main control circuit may be disabled until the lock is removed. The evolution of safety circuits has already begun.

Of course, this base is a relay station. A relay that provides a safe way to reduce the power of the device should be more robust than a normal relay. A term called "force conductance" was thus coined. These relays are constructed in such a way that there is only one on state and one off state.

Other manufacturers proposed that if one relay was safe, two would be safer. Safety circuits evolved to use two relays in series as a means of ensuring that the failure of one relay would cause the failure of the entire circuit.

As with any evolution, there are sidesteps in the developing world of security. Around the time of the appearance of the dual safety circuit, the concept of the dual circuit of the safety device appeared. This thought process stems from the idea that if one circuit driving both relays is safe, then both circuits driving both relays need to be intact, which would be safer.