9/4/2019 7:24 AM | |
Joined: 3/17/2013 Last visit: 8/25/2024 Posts: 481 Rating:
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Hi in our plant we are using CPU 6ES7-414-4HM14-0AB0 fail safe IO modules and normal IO modules. I wish to know what are the advantages of Fail safe IO without fail safe CPU. If I am using a field side proximity P & F and switching amplifier of SIL2 rated, does the loop not deviating from IO card feature of SIL3 rating. Regards Vijay ------------------------------------------------------------------------------------------ |
Last edited by: Jen_Moderator at: 09/04/2019 08:05:48New subject after splitting |
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9/14/2019 4:51 AM | |
Joined: 9/9/2015 Last visit: 9/4/2024 Posts: 727 Rating:
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Dear N.Vijay, As far as I know, there are two reasons why we need to use F-module. The first is because of the certificate, it is certified up to SIL 3. You may refer to the certificate here. TUV certificate. If the system requirement called for IEC61508 or IEC61511, you have no choice but to use Safety program, safety logic solver and safety module to design your architecture. The second reasons are, you required a line monitoring. Let me give you an example, for standard DO module, you can use a multimeter to measure the DO channel voltage even there is no load connecting the DO channel. The DO module does not have any smart feature to detect whether there is a load connecting it. For F-DO module, you cannot. You must connect it with a 2.2kohm resistor and measure the voltage in parallel. It will know if there is no load connecting it. It will have special function like protection against short circuit and overload (giving you a specific diagnostic alarm in HMI), operation in safe mode, display of channel-specific errors from Green LED to Red LED, programmable diagnostic function, Channel selective passivation, proof test interval of 20 years and MTTR of 100hours. It consists of a light test and dark test function, wire break monitoring as well. When passivated, you could have a maintenance override capability to set the PASS_ON to 0 or reintegrate the specific channel to when the channel back to a healthy state. All the procedure in F System is following the IEC61511 guideline. Hence, you may take a look at IEC61511 part 1 to have more information. Conclusion, there is a huge difference between the standard and F module. Hope this piece of information is helpful for you. |
Last edited by: JazTai at: 09/14/2019 04:53:58Please give me 5 stars Rating if my post is helpful for you. :) |
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