Re: CAN bus and PPC processors

[John Maclean <jfm@aps.anl.gov>]

Hi Geoff

Geoff Savage wrote:
>  Has anyone
> attempted to use the TIP810 on a PPC board?  Any idea how hard this
> might be to implement?  

It would be very hard. Motorola PPC boards don't have IP slots :)

> The alternative is to use an EPICS supported
> IPAC card.  This would be the more expensive solution in terms of 
> equipment.

The SBS VIPC616 IP carrier card is ~ $500, so it's not too expensive. 
There are issues with this card concerning interrupt daisy chaining. We 
always put them on the right hand side of the crate for this reason. 
People who use the hytec carrier seem very happy with it. That one costs 
~ $1100 though.

I know that Gemini use a PPC with a SBS carrier that has 4 TIP810s on. 
Last I knew this was working fine.

> Is a CAN bus controller that plugs directly into the VME bus a better
> option?

It always used to be more expensive. I don't know what's on the market 
now though.

> The run from the CAN bus interface to the the power supply is about 100
> feet.  Will this distance have an impact on operations?

IIRC > 40m will limit it to 500 kbps, so you may get away with 1 Mbps, 
but check the CAN spec.

John.