What is the future trend at the machine manufacturers? (for safety sensor and controler)
CAN Safety or CAN Redundant?
ddellorto: | ||
I personally think that for sensors the ""world"" will move to Can Open Safety, I see very difficult to have always on a sensor 2 independent and redundant CAN Bus Line. It is much easier to add a message to the same line to double the information than add a physical line. My experience is that OEMs prefer to have only one Can Bus line on the machine. The hardware is always the CAN 2.0b nothing change in terms of hardware, it is just a matter of how many buses there are. Practically talking there are 100 ways to increase safety. For CAN Bus we already have something like 0,000000001 possibility to have a wrong message and if the system works with messages sent cyclically we can have 1 error every 1 billion of messages sent. Imagine for example a cycle time of 100mS. It means 36000 messages per hour. 360000 messages in a 10 hours working day. Do we want to think about a very loaded line with 100 messages every cycle, we will have 36 millions of messages in a day, it would be any way very difficult to have an error and, by the cyclic modality, very hard to do not recover from a possible error… A lot of rules are commercial things the important it is always to think and to understand what we are doing.
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09.12.2015 |
hrathod: | ||
Keeping standards apart for a while and thinking of application point of view than System being redundant is a sort of Safety.
However in requirement to hardware implement CAN Safety and Redundant may differ, Ultimately customer demand is what all it takes. |
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09.12.2015 |
ahorn: | ||
I also think we will have both solutions in the future. Once an OEM deceided for either CANOpen Safety or CAN redundant it's hard to change the concept. Furthermore there are meanwhile a great range of products for both solutions.
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09.12.2015 |
gsalemme: | ||
If ""Necessity is the Mother of Invention"" then legislation and safety are its twin daughters
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09.12.2015 |
aholleyn: | ||
Even if only one bus on the machine is available , a decrease in accordance with EN ISO 13849 and SIL 2 can be achieved by special mechanisms with standard CANopen. But ultimately decides the customer and it is always useful to be able to offer both.
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09.12.2015 |