Re: [ARTIQ] starter ARTIQ hardware for neutral atoms
> > > On Wednesday, March 08, 2017 06:11 AM, Neal Pisenti via ARTIQ wrote: > > * For ARTIQ core device, we would ideally jump straight to using a > > Kasli, but as that isn't likely to be done in the next few months, I was > > planning to use a KC705 as the core. > > The "EEM" DDS/synth Kasli extensions may not necessarily be ready before > Kasli. So I don't see how the KC705 helps - is it because you want more > extensions that one Kasli would support? Supporting this KC705 scheme is > more gateware development and one more configuration that needs to be > documented, packaged and maintained. Maintainance means that we need to > check regularly (preferably automatically) that it keeps working when we > modify ARTIQ and fix any bugs that pop up. It takes work. > Valid point -- my main thought with this setup is exactly what Tom articulated; the KC705 -> VHDCI is a stopgap until Metlino/Kasli development is completed. And it would allow us to start using digital IO immediately via the PCB_3U_BNC EEM, and we might spin up some in-house boards for multichannel DAC over SPI. We shouldn't need the DDS/synth modules for some time still, since all of our DDS currently exist as "slow peripherals" in the artiq sense. The other short-term alternative I see is adapting either the nist_clock or nist_qc2 builds, and making our own FMC -> ___ breakout. But piggybacking on the EEM architecture seems cleaner and more future-proof. When the Kasli is done, we would either abandon the KC705 for a Kasli as core, or (depending on the cost) plan for 1x Kasli as DRTIO connected to the KC705 SFP. That would certainly put a limit on how many things we can control, but will probably satisfy our needs in the foreseeable future. Even though the uTCA/Metlino setup will be exceedingly nice, for neutral atom experiments it is currently overkill. But whether the upfront cost of a uTCA chassis & associated hardware is worth additional development headache to exclusively use Kasli baords...? Remains to be seen. > * KC705 has 2x FMC headers, which would drive 1x VHDCI carrier card, > > providing 8x IDC for EEMs. We would buy FMC -> VHDCI adapters for this > > interconnect. > > What adapters in particular? http://www.ohwr.org/projects/fmc-vhdci? We > didn't check compatibility of any of those. > When I chatted with Joe, we looked at this one: http://www.ohwr.org/projects/fmc-dio-32chlvdsa/wiki/Wiki @Greg -- are the board files available for this? I looked on the Creotech website but couldn't find it for sale anywhere (which is odd, because I swear I saw it there before, for ~ $500). Even so, I wonder about pricing it out at MacroFab or one of these other small-turn PCB companies before spending $1k on a pair of them. Cheers, Neal ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
Re: [ARTIQ] starter ARTIQ hardware for neutral atoms
Hi, On Wednesday, March 08, 2017 06:11 AM, Neal Pisenti via ARTIQ wrote: * For ARTIQ core device, we would ideally jump straight to using a Kasli, but as that isn't likely to be done in the next few months, I was planning to use a KC705 as the core. The "EEM" DDS/synth Kasli extensions may not necessarily be ready before Kasli. So I don't see how the KC705 helps - is it because you want more extensions that one Kasli would support? Supporting this KC705 scheme is more gateware development and one more configuration that needs to be documented, packaged and maintained. Maintainance means that we need to check regularly (preferably automatically) that it keeps working when we modify ARTIQ and fix any bugs that pop up. It takes work. * KC705 has 2x FMC headers, which would drive 1x VHDCI carrier card, providing 8x IDC for EEMs. We would buy FMC -> VHDCI adapters for this interconnect. What adapters in particular? http://www.ohwr.org/projects/fmc-vhdci? We didn't check compatibility of any of those. **Specific questions**: * what limitations are there (latency/bandwidth/etc) on daisy-chaining additional Kasili DRTIO modules off of the single KC705 SFP? While the hardware could do it, daisy-chaining Kaslis is not supported by the current gateware plans. The plan is to use a Metlino, which has many available transceiver links (mostly to the microTCA backplane, but there are also 3 SFPs), as a central device with a direct link to every satellite device. If daisy-chains are implemented, there would be virtually no impact on bandwidth, and the latency would increase by roughly ~100-200ns per hop. Instead of the daisy chain, it is also possible to have one Kasli as central device driving directly other Kaslis with its SFPs (note that one SFP will be used for Ethernet). There are no current gateware plans for this either (so this would need funding), but it is less difficult to develop and has less latency. * Is there an estimate on the timescale for finished Kasli? It is not funded yet, but I think this should happen in a few months. Then there will be another few months before it begins to become usable. Sébastien ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
[ARTIQ] starter ARTIQ hardware for neutral atoms
Hi all, The strontium lab at the JQI is finalizing the computer control system for our new experiment, and I am finally revisiting ARTIQ to figure out what hardware we need. Our current experiment uses the following: * 48 digital outputs (8 are designated as triggers for other devices) * 24 analog outputs (from NI's PCI-6733 DAC cards) * several (~8?) homebuilt DDSs, which aren't phase synchronized but have profile-select control for hopping frequencies/initiating simple frequency ramps with ~ < 1ms latencies. * Point Grey / PIXIS cameras for image acquisition, currently analyzed "offline" between experimental shots * For analog ramps, the fastest update rate we currently use is 10us/sample (although that also has to do with our shitty labview control interface, which can crash if your DAC sample buffer gets too long...) * Eurocard 19" rack enclosures are already used for most of our custom electronics; we like this form factor. That all said, in the new system we would like * A few phase synchronized DDS (likely operated at 30-50MHz), eg, for fancier lattice AOM control, feed forward/feedback on narrowline clock laser, ... other * analog input * upgraded analog output to move away from NI; some channels with PDQ-esque AWG capability, although most of our analog control needs are relatively slow. * more analog/digital I/O for future expansion. Given those requirements, here's what I'm thinking to buy in the short & longer term. Since we're still building the vacuum chamber, many of the "fancy" control requirements are many months away. I was hoping to get input/feedback/suggestions as to whether this plan sounds good: * For ARTIQ core device, we would ideally jump straight to using a Kasli, but as that isn't likely to be done in the next few months, I was planning to use a KC705 as the core. * KC705 has 2x FMC headers, which would drive 1x VHDCI carrier card, providing 8x IDC for EEMs. We would buy FMC -> VHDCI adapters for this interconnect. >From 8 EEM headers, we could get: * 6x BNC EEMs -> 48 DIO * 2x EEMs for... analog IO? Initially, we could continue to use the 6733 DACs, but longer term switch to Zotino/PDQ/... It seems we will eventually want at least one Kasli expansion DRTIO module. This would be connected on the KC705 SFP. **Specific questions**: * what limitations are there (latency/bandwidth/etc) on daisy-chaining additional Kasili DRTIO modules off of the single KC705 SFP? * What IO mapping needs to be done to support KC705 as a core driving EEMs over the two FMC connectors? Is there any plan to allow the HPC connector to drive an entire VHDCI adapter on it's own (thus expanding the KC705 to drive 12 EEM modules, 1x from the HPC + 0.5x from the LPC), and is this even desirable over, say, adding a Kasli over DRTIO? * Is there an estimate on the timescale for finished Kasli? * Should I reconsider any of this approach, or does it seem reasonable? Any other suggestions/advice? Thanks in advance for the input! Neal ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
