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Working Principle of Safety Relay Module

Ⅰ. Historical context for the development of safety relay modules


With the rise in safety regulations, safety circuits were added. Machines and equipment have become more complex and powerful as a result of the development of automatic control technology at the end of the twentieth century, posing a greater risk of safety issues and losses than ever before, and learning how to operate these devices safely and properly, so that they can perform properly, which is becoming an increasingly urgent issue in the production and lives of those involved. The small safety relay module is the basic electrical component of the control circuit, which controls the contact system's switching by controlling the energisation of its coils, which in turn controls the switching of other switchgear, and ultimately a certain control logic through the switching and breaking of the circuit. The control logic in this system is achieved through the normal function of each device, but it is not uncommon for a device's function to be abnormal, causing the system to fail to function or, in more serious cases, to operate incorrectly, resulting in serious safety accidents involving casualties and equipment damage.


Ⅱ. The safety relay module is a solution to the problem mentioned above


Accidents can be prevented if you can ensure that the machine stops and does not work in the case of a functional anomaly in a device (since you cannot guarantee that all devices will be undamaged and normal throughout operation). A normal functional circuit is the input to the safety circuit, and if there is an irregularity in the functional circuit, the safety circuit outputs a disconnected state, shutting off power to the functional circuit and permitting a shutdown.


The safety relay module, which is utilized to monitor the functional circuit, is the main component of the safety circuit. If the state of the functional circuit is normal (the device is intact and normal, the function is realized), the safety relay module outputs a closed state, the power to the functional circuit is switched on, and the function is realized; if the state of the functional circuit is abnormal (the device is faulty, the function changes), the safety relay module outputs an open state, the power to the functional circuit is switched on, and the function is realized; if the state of the functional circuit is abnormal (the device is faulty, The functional circuit is switched off and the function is shut down when the safety relay module outputs a closed condition.


In other words, the shutdown is carried out by the functional circuit in the absence of a safety relay module, which is the main component of the safety circuit, after the control system has checked for anomalies and issued a disconnection signal. The detection system, the control system, and the action system are all involved in this process, and their functional integrity determines the safety of the entire machine: the sensing system's reliability, the control system's software collapse, and the action system's adhesion can all lead to a failure of the safety stop, resulting in an accident.


The safety circuit's safety module continuously detects functional abnormalities via dual channels, greatly reducing the likelihood of a fault in the inspection sensing system leading to a system miscalculation; in the event of an abnormality, the safety relay module automatically outputs a disconnect state, cutting off the power supply to the functional circuit and allowing a shutdown. The appearance of the safety module disconnection output state is unaffected by whether the control system issues a disconnection command at this point, which can prevent safety malfunctions due to the collapse of the control system function: each time the safety module is activated, the normal function of the action system will be checked and confirmed through feedback; if the function is normal, the safety module will be activated; if the function is abnormal, the safety module will be deactivated.


The safety relay module, which is the basic component for establishing the safety circuit, will decide if the safety circuit can work in this system! How can we ensure that the safety relay module, as a circuit component, will not fail if we can't guarantee that any of the components will stay structurally sound and functioning throughout operation?


The safety relay module, like any other device, can be damaged. However, regardless of its fault condition, one of its outputs will either send a break signal, or the safety output will break (it has an internal double tolerance design - the probability of simultaneous sticking is lower than for a single functional circuit), or the safety signal will break (notifying the control system of the break command). Regardless, the control system is notified of the disconnecting instruction! This guarantees that the safety function is maintained even if the safety relay module fails! The safety relay module's most essential feature is this.


Because the safety relay, which is the main component of the safety relay module, has a forced disconnection design, the safety relay module has this functionality! (See the difference between a safety relay and a standard relay for further information on the safety relay's forced disconnection function.)

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