RE: Non Powered Devices

Good to know.  Thanks
John
 
 
From: [email protected] [mailto:[email protected]] On Behalf
Of Al Thomason
Sent: July-04-18 11:39 AM
To: [email protected]; [email protected]
Subject: RE: [CANLIST] Non Powered Devices
 
Snipped from the MCP2551 datasheet:  "An unpowered node or brown-out event
will not disturb the CAN bus"
 
 
MCP2561 has like language.  IIRC, all other 'modern' transceivers take care
to not disturbed the CAN bus while powered-down.
 
-al-
 
 
Viking Star
45' Monk Sr. / McQueen
mvVikingStar.blogspot.com
 
From: [email protected] [mailto:[email protected]] On Behalf
Of Kees Zagers
Sent: Wednesday, July 04, 2018 5:24 AM
To: [email protected]
Subject: Re: [CANLIST] Non Powered Devices
 
Hi John,
Waking up the list again :-)
As far as I know this problem only occured at the old 250 driver. Since the
251 all CAN transceivers should be well protected and also don't influence
the bus if they are not powered. I mostly use NXP and Microchip transceivers
and did not notice any disturbance with non-powered devices connected to the
bus. They behave as very high impedance inputs.
Kees
 
Op 4-7-2018 om 02:19 schreef John Dammeyer:
Way back at the beginning it was pretty well a rule that all nodes on a CAN
bus should be powered.  With Steve Corrigan from TI no longer with us I
don't have access to a CAN driver designer to ask that question.   And there
are way more drivers out there than there were 25 years ago.
 
What's the general rule on that now?   Will an unpowered CAN driver
adversely affect the CAN bus signals and/or are there some that can even be
damaged?
 
Thanks
John Dammeyer
 
 
 
 
"ELS! Nothing else works as well for your Lathe"
Automation Artisans Inc.
www dot autoartisans dot com