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Is this considered a Failsafe digital output configuration?

Created by: AMAZINGAHMED at: 7/9/2013 9:18 PM (4 Replies)

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7/9/2013 9:18 PM	Rate (0)
AMAZINGAHMED Gold Member Joined: 8/27/2006 Last visit: 9/2/2024 Posts: 719 Rating: (88)	I was wondering about failsafe digital output modules what is special aboul them? dignostics? If I get for a 32 digital output module a 32 digita input module and I wired the each digital output signal to a digital input channel (i.e. Q0.0 -> I0.0, Q0.1 -> I0.1, ...etc) as well as connecting them to their field devices (relays, valves,...) In this way, I can diagnose a channel by channel for the digital output module, and if one digital output channel is faulty I will know for sure. The question is : Is this considered a failsafe digital output module?
	The more you know, The more you know that you don't know
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7/10/2013 12:29 AM	Rate (0)
Ayman Elotaify Platinum Expert Joined: 5/28/2008 Last visit: 9/9/2024 Posts: 4515 Rating: (839)	AMAZINGAHMED I was wondering about failsafe digital output modules what is special aboul them? dignostics? If I get for a 32 digital output module a 32 digita input module and I wired the each digital output signal to a digital input channel (i.e. Q0.0 -> I0.0, Q0.1 -> I0.1, ...etc) as well as connecting them to their field devices (relays, valves,...) In this way, I can diagnose a channel by channel for the digital output module, and if one digital output channel is faulty I will know for sure. The question is : Is this considered a failsafe digital output module? Hello, No it is not a fail safe system. coz you did made all tests and you did not used certified blocks as well. Deference Between Fail safe & Standard Systems
	Ayman Elotaify
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7/10/2013 7:22 AM	Rate (0)
AMAZINGAHMED Gold Member Joined: 8/27/2006 Last visit: 9/2/2024 Posts: 719 Rating: (88)	Ayman Elotaify AMAZINGAHMED I was wondering about failsafe digital output modules what is special aboul them? dignostics? If I get for a 32 digital output module a 32 digita input module and I wired the each digital output signal to a digital input channel (i.e. Q0.0 -> I0.0, Q0.1 -> I0.1, ...etc) as well as connecting them to their field devices (relays, valves,...) In this way, I can diagnose a channel by channel for the digital output module, and if one digital output channel is faulty I will know for sure. The question is : Is this considered a failsafe digital output module? Hello, No it is not a fail safe system. coz you did made all tests and you did not used certified blocks as well. Deference Between Fail safe & Standard Systems Yes, but I saw this technique is been used in old failsafe Step5 PLCs (e.g. CPU115F). The failsafe 16 digital output is divided into two halfs. 16 DO and 16 DI. The output is connected to the input as well as the field device. This module itself is described as 16DO failsafe.
	The more you know, The more you know that you don't know
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7/10/2013 10:36 AM	Rate (0)
Ayman Elotaify Platinum Expert Joined: 5/28/2008 Last visit: 9/9/2024 Posts: 4515 Rating: (839)	AMAZINGAHMED Yes, but I saw this technique is been used in old failsafe Step5 PLCs (e.g. CPU115F). The failsafe 16 digital output is divided into two halfs. 16 DO and 16 DI. The output is connected to the input as well as the field device. This module itself is described as 16DO failsafe. Hello Ahmed, I do not have experience with S5-Fail Safe Systems. And I am not sure that the above behavior is the ideal or best engineering.
	Ayman Elotaify
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7/10/2013 11:03 AM	Rate (0)
yy1 Gold Member Joined: 3/24/2009 Last visit: 7/9/2024 Posts: 535 Rating: (112)	Ayman Elotaify And I am not sure that the above behavior is the ideal or best engineering. Dear AMAZINGAHMED, I also think, that you will have to do much more to prove the safety of your plant, as when you use certified F-IO modules, which have a lot of integrated background-tests (here an article for sinamics) Best regards, yy1

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