#8 Skip ROM voltage convert for DS2438 VAD

accepted
Paul Alfille
None
5
2014-09-23
2010-03-09
Andrew Radke
No

Hi,

When checking VAD voltages on DS2438's it would be good to use skip rom voltage convert ('bCCB4' in the Link ASCII commands) to save significant time when querying a number of devices. This could work with the volatile object cache timings as a way to know if another voltage convert command is needed when querying another DS2438.

For us when dealing with around 60 DS2438 devices on one bus issuing the voltage convert on a device by device basis can take far longer than a skip rom voltage convert followed by individual read commands.

Hopefully this is something that could be relatively easily incorporated and maybe other skip rom commands could be added for other devices/queries as well.

Regards,
Andrew

Discussion

  • Paul Alfille
    Paul Alfille
    2010-03-09

    The DS2438 doesn't support RESUME ROM. Using SKIP ROM only works if there are no other slaves on the wire. It's not a good fit for OWFS.

    Paul Alfille

     
  • Andrew Radke
    Andrew Radke
    2010-03-09

    Issuing a skip rom followed by reading all values on the ds2438 does work with at least ds18b20, ds18s20, ds2401 and ds2423. I have around 80 ds2438 slaves mixed with these other devices across 4 buses (around 40 would be on one) with no problems in this scenario.

     
  • Paul Alfille
    Paul Alfille
    2014-09-23

    • Status: open --> accepted
     


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