| ??? 11/27/10 06:54 Read: times |
#179680 - taken care Responding to: ???'s previous message |
Michael Karas said:
Highly redundant systems demand way more than dual watchdogs. You could have failures in the program counter, in the oscillator, in the code memory, in the data memory, in the accumulator, in register 7, in the ... in the ............. (name another system part).
Then consider that the MCU subsystem does not experience a hard failure but instead a soft failure that corrupts code execution or leads to circuit latchup that requires a power cycle to recover from. If you are studying the highest in reliable systems you would be best to focus on building the whole system in triplicate and then coordinate their code execution through some type of interactive 3-way polling and monitoring system. Michael Karas All these things are being taken care. As they are the basic requirement of SIL certification |
| Topic | Author | Date |
| dual watchdog timer | 01/01/70 00:00 | |
| Scope | 01/01/70 00:00 | |
| maybe wrong site for the question but !!!!!!!!!!!!!!! | 01/01/70 00:00 | |
| You still haven't said... | 01/01/70 00:00 | |
| WDT failure | 01/01/70 00:00 | |
| Dual oscillator | 01/01/70 00:00 | |
| Do you need high reliability? | 01/01/70 00:00 | |
| IEC61508 | 01/01/70 00:00 | |
| Supervisor with WDT | 01/01/70 00:00 | |
| Since you are considering an 805x ... | 01/01/70 00:00 | |
| If one watchdog fails... | 01/01/70 00:00 | |
| the 1232 is external ... remember? | 01/01/70 00:00 | |
| Yes; that was my point - I was agreeing with you! | 01/01/70 00:00 | |
| Sorry! I didn't follow. | 01/01/70 00:00 | |
| Highly Redundant Systems | 01/01/70 00:00 | |
| a bit off the topic, but | 01/01/70 00:00 | |
| it's a matter of statistical probability | 01/01/70 00:00 | |
| Not required for 61508 | 01/01/70 00:00 | |
taken care | 01/01/70 00:00 |