Re: CAEN VME crate with controller card plus digitizers

["Dmitry Yu. Bolkhovityanov via Tech-talk" <tech-talk at aps.anl.gov>]

On Mon, 19 Jul 2021, Michael Davidsaver via Tech-talk wrote:

> On 7/19/21 11:47 AM, Josh Fiddler via Tech-talk wrote:
> > Greetings everyone, 
> >
> > My current task involves implementing support for reading waveforms from a CAEN V1740 <https://www.caen.it/products/v1740/> Digitizer card installed in a CAEN 8008B VME crate <https://www.caen.it/products/vme8008b/> with the V1718 USB2 Bridge. They provide libraries for grabbing data with a CL application, but I want to ask if anyone has experience with this family of devices from CAEN.
>
> Have you investigated OS and/or EPICS support for this V1718 USB2 to VME bridge?
>
> USB communication is inherently message based.  All of the VME bridge drivers
> in the EPICS world which I'm aware of assume memory mapped I/O.  So with this
> bridge, I would not expect any of the existing EPICS VME drivers and utilities
> to be immediately useful.

Just a small clarification (from a person who had spent some time working 
with CAEN VME hardware): yes, CAEN provides a "function call" API via 
CAENVMElib, not a memory-mapped I/O.  The API is unified along all kinds 
of adapters -- USB, PCI, PCIe.  Adapters connect to VME controllers via 
optical links (CAEN private "CONET2" protocol, but optical media is the 
same as used for optical Ethernet).

This API consists of
1) usual bus open/close functions CAENVME_Init() and CAENVME_End();
2) VME I/O functions CAENVME_ReadCycle(), CAENVME_WriteCycle and their 
BLT-versions.  There is NO notion of "windows" and address modifiers are 
specified directly with each *Cycle() call.

IRQ handling is a bit quirky: there's no direct way to catch an interrupt 
but just a polling is possible via CAENVME_IRQWait() and 
CAENVME_IRQCheck().

AFAIK, Evgeny Simonov from our institute had successfully implemented some 
EPICS support for CAEN A3818+V2718 adapter+controller; I'm CC:'ing him.

	_________________________________________
	  Dmitry Yu. Bolkhovityanov
	  The Budker Institute of Nuclear Physics
	  Novosibirsk, Russia