Advantages of Safety PLC

Why Safety PLC…??? Even more functionality available in Conventional PLC ?

Safety & Conventional PLC can both control things, while the conventional PLC will probably offer more features, less cost, be more readily available,

Now Concern is requirement of:-

A. Shutdown a system if anything goes wrong.

B. Safely Shutdown a system if anything goes wrong.

Using a Conventional PLC for a Safety Circuit-

Conventional PLC can be programmed however we want. A system can be designed and programmed with any level of complication with a PLC .We can detect any kind of failure and put the equipment in a stopped, safe and controlled manner.

But, the consequence are:-

a- Problems increase with increase in relays and can quickly get complicated

b- Poor diagnostics and poor status indicators

c- Very difficult to do multiple e-stop zones

Using a Safety PLC for a Safety Circuit-

A safety PLC is different from a conventional PLC in many ways, such as:

  1. Redundancy of onboard devices which are continuously monitored by a watchdog timer.

  2. Continuously monitors inputs with a smart circuit to detect failure.

  3. Added safety circuitry between the output switching device and an actual device, which will detect system failure and facilitate a safe shut down by going back to a known state.

Major savings on field wiring, Remote I/O capability with safety, Good diagnostic capability can be easily achieved by Safety PLC.

Definitely, if we see consequence then there is:-

a. cost is higher

b. Requires Safety programming

c. Possibly too complex for applications

d. Understand System & Application, Hazardous study of & System Citification

e. Requires educated maintenance people

Credits - Amit Upadhyay