On Thu, Mar 7, 2013, at 12:12 PM, Daniel Rogge wrote: > >But surely it gets set to the correct value by the gearlever > >microswitch approximately 1mS later? > > If you have a microswitch on your gearlever! >
Seb's point is still relevant. The scaling of motor speed to shaft speed depends on what gear the gearbox is actually in - that involves the physical position of pieces of metal, not bits stored on a disk. If a design is based on having the gearchange component remember that the gearbox was in low gear when the machine was last powered down, it is only a matter of time until something goes wrong. What happens if someone manually changes gears while the machine is powered down? In this specific example, the "persistance" is done by the actual gearbox, and the component ought to get its state from the gearbox (by microswitches or whatever else). Adding persistance to the HAL component means that you are storing the same thing (gearbox setting) in two places - the box itself and the HAL component. It is inevitable that sooner or later they will get out of sync. There may be other good use cases for HAL persistance, but IMHO this isn't one. Like Matt and Seb, I'd like to understand the use case for HAL persistance before we talk about where it belongs. -- John Kasunich jmkasun...@fastmail.fm ------------------------------------------------------------------------------ Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the endpoint security space. For insight on selecting the right partner to tackle endpoint security challenges, access the full report. http://p.sf.net/sfu/symantec-dev2dev _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
