Upgrading Blackrock for more analog channels

Yasmine El-Shamayleh's Avatar

Yasmine El-Shamayleh

06 Nov, 2020 03:48 PM

Hi Chris -

Hope you're well. Just wanted to run something by you quick.

I've been talking to Blackrock about needing more than 3 analog channels on my recordings system for my optogenetics experiments (2 channels for eyelink and up to 4 channels for the laser). As you might remember, the goal will be to send all analog and digital events to blackrock and to use ViewPixx digital out as a time-stamping signal.

Blackrock is happy to upgrade my new/unused low-end system for one that satisfies these criteria (for $20K extra). It's a bit much - but I figure it will streamline our experiments and this is what startup funds are there for. But before I go ahead with this, I wanted to share the specs and ask a few questions.

The upgraded system would have 32 neural channels in addition to the following:
16 channels of analog in
16 channels of analog out
4 channels of analog in
4 channels of analog out

I think this will be enough for my needs - but I'll be honest that I'm not entirely sure how MWorks will communicate with Blackrock. Will it be via the ViewPixx digital outputs (DB25 pin cable)? Or another way?

Blackrock mentioned something about needing a "Network gigabit switch with Quality of Service (QUS)" to connect the MWorks computer to Blackrock - but I'll admit that I'm not sure what that is! Is this some kind of ethernet-based connection?

Would appreciate your input on this!

Thanks!
Yasmine

  1. 1 Posted by Yasmine El-Sham... on 06 Nov, 2020 04:06 PM

    Yasmine El-Shamayleh's Avatar

    Correcting some typos in my last email:

    The upgraded Blackrock system would have 32 neural channels in addition to the following:
    16 analog in, 16 digital in, 4 analog out, 4 digital out.

  2. Support Staff 2 Posted by Christopher Sta... on 06 Nov, 2020 04:57 PM

    Christopher Stawarz's Avatar

    Hi Yasmine,

    I'm not very familiar with Blackrock's products, but it sounds like you're replacing a CerePlex Direct with a Cerebus. Is that correct?

    (2 channels for eyelink and up to 4 channels for the laser)

    Just curious: All the eye position data will already be saved to the MWorks event file. Although we haven't implemented the laser interface yet, presumably the laser settings and trigger events will go to the event file, too. Do you want all this stuff to also be recorded by the Blackrock system just as a backup? Or are you sending it there so that it's recorded on the same clock as the neural data? Or some other reason? (I'm not trying to critique your design, just understand it.)

    I think this will be enough for my needs - but I'll be honest that I'm not entirely sure how MWorks will communicate with Blackrock. Will it be via the ViewPixx digital outputs (DB25 pin cable)? Or another way?

    Yes, you'll connect the digital output lines on the DB-25 connector to the digital inputs on the Blackrock system. On the Cerebus, it looks like the digital inputs are exposed via a DB-37 connector, so you'll need some kind of adaptor in between to match output pins to input pins.

    Blackrock mentioned something about needing a "Network gigabit switch with Quality of Service (QUS)" to connect the MWorks computer to Blackrock - but I'll admit that I'm not sure what that is! Is this some kind of ethernet-based connection?

    I don't think they understood that you'll be running MWorks on a Mac.

    To control the Blackrock system, you'll need a separate Windows PC (not included). The Cerebus product page says the PC should have a gigabit Ethernet port. I would think you could connect that port directly to the port on the Cerebus via an Ethernet cable, with no switch required, but maybe not.

    In any case, I think they made a point of this just because the CerePlex Direct connects to the Windows PC via USB, so if you'd already purchased a PC to work with it, you might not have gotten one with gigabit Ethernet.

    Cheers,
    Chris

  3. 3 Posted by Yasmine El-Sham... on 06 Nov, 2020 05:31 PM

    Yasmine El-Shamayleh's Avatar

    Hi Chris -

    Always appreciate your input on this!

    I'm 100% open to design critiques. I'm not a pro at setting up rigs so
    always happy to hear about better ways to do things.

    Let me answer your few questions below. I'm also CCing Kian and Joey from
    Blackrock who have kindly agreed to be looped in to help out with these
    decisions.

    *I'm not very familiar with Blackrock's products, but it sounds like you're
    replacing a CerePlex Direct
    <https://www.blackrockmicro.com/neuroscience-research-products/neural-data-acquisition-systems/cereplex-direct-daq/>
    with
    a Cerebus
    <https://www.blackrockmicro.com/neuroscience-research-products/neural-data-acquisition-systems/cerebus-daq-system/>.
    Is that correct*

    Yasmine: Correct!

    *Just curious: All the eye position data will already be saved to the
    MWorks event file. Although we haven't implemented the laser interface yet,
    presumably the laser settings and trigger events will go to the event file,
    too. Do you want all this stuff to also be recorded by the Blackrock system
    just as a backup? Or are you sending it there so that it's recorded on the
    same clock as the neural data? Or some other reason? (I'm not trying to
    critique your design, just understand it.)*

    Yasmine: Yes - I need to save a time-stamped analog trace of the light
    pattern emitted by the laser diode along with the neural data for analysis
    later. I don't think that having the digital events from MWorks is
    sufficient for two reasons: (1) the laser can have some non-linearities
    (especially in the case of fast/repeated stimulation) that we might not
    pick up otherwise -- (2) the MWorks file might say that we're triggering
    the laser but this unit could be malfunctioning or powered down and we
    wouldn't know it! For this reason, as a postdoc, I've found it super useful
    to have an analog trace of the laser that is saved alongside the neural
    data. Finally, re: Eyelink inputs, my understanding is that MWorks is only
    getting digital Eyelink inputs -- but it will be good to save the more
    accurate analog Eyelink inputs with the neural data (especially necessary
    for recording from early visual areas).

    *Yes, you'll connect the digital output lines on the DB-25 connector to the
    digital inputs on the Blackrock system. On the Cerebus, it looks like the
    digital inputs are exposed via a DB-37 connector, so you'll need some kind
    of adaptor in between to match output pins to input pins.*

    Yasmine: OK.

    @Kian and Joey: MWorks will communicate with Blackrock via the digital
    outputs of our ViewPixx monitor (DB25 cable). Any suggestions for how to
    make an appropriate adaptor for doing from DB25 to DB-37? And in this case,
    if MWorks is sending digital inputs to blackrock via the DB25 cable, then
    am I right that we will not need a QUS network gigabit switch???

    Thanks everyone!

    Yasmine

  4. Christopher Stawarz closed this discussion on 20 Jan, 2021 01:42 PM.

Comments are currently closed for this discussion. You can start a new one.

Keyboard shortcuts

Generic

? Show this help
ESC Blurs the current field

Comment Form

r Focus the comment reply box
^ + ↩ Submit the comment

You can use Command ⌘ instead of Control ^ on Mac