2-laptop setup, parallel port problem

[magnuson]

Hi,

We are trying to prep our system for fieldwork. We will need to use 2 laptops. But we have run into a big problem with the parallel port.

Is there a parallel port adapter that will work with a modern laptop (with express ports instead of PCMCIA)? If anyone can recommend one, or if there are work arounds for using a usb-based adapter, etc., I would greatly appreciate any advice.

Thanks,

jim

[Coen]

viewtopic.php?p=988

Best regards, Coen (BioSemi)

[magnuson]

That topic does not seem to help. It describes PCMCIA adapters. It mentions that an express adapter had been purchased but not tested.

Current laptops do not come with PCMCIA ports.

I've heard from the US distributor that a simple startech Express->parallel adapter may work.

[Lloyd]

I should first clarify that ActiveTwo does not require a parallel port. It requires only a USB2 port on the ActiveTwo host computer.

Users of ActiveTwo who are investigating event-related brain potentials and are using software like E-Prime or Presentation to deliver stimuli to a subject will need a parallel port on the computer running their stimulus delivery software if they intend to send synchronous coded triggers to ActiveTwo's digital input port.

On modern laptop/notebook computers, parallel ports are rare, and PCMCIA (CardBus) has been replaced by ExpressCard slots on most notebooks. We routinely use ExpressCard parallel port cards to send triggers from a laptop to ActiveTwo, and I have tested and confirmed that the timing is as good as a PCI parallel port - it is accurate to within one msec. The ExpressCard slot is a reliable solution to sending triggers from a laptop/notebook PC.

An alternative that many people have considered is a USB-to-parallel converter device. I strongly recommend against using one of these because of known inherent timing problems - USB output can have unpredictable timing with jitter on the order of 30 msec.

If you are using a MAC and have no other option, then you may consider using something like the IOLAB USB button box made for PsyScope to send triggers to ActiveTwo, but be aware that its USB interface to the PC is an inherent drawback and you should test this configuration before assuming it will produce accurately timed triggers.

[bburt]

Just to clarify - to get this USB receiver to accept pulses using a modern laptop, I'd need to get an ExpressCard to parallel adapter, then have a custom cable made to go from DB-25 to the 37-pin sub-D input on the USB box?

Seems complicated. If I've correctly understood this, I sure wish that BioSemi had stuck with a DB-25 parallel cable, as we've previously used.

[Coen]

BioSemi uses a 37 <--> 25 pole parallel cable since the introduction of the USB receiver (exactly 7 years ago). The cable is supplied by us as a standard accessory since 2005. By the way, the 25 <--> 25 pole parallel cable used before 2003 wasn't a standard printer cable either.

Best regards, Coen (BioSemi)

[Robbie303]

Cedrus sells a USB to Parallel converter that is instantly compatible between the Presentation software of Mindware Technologies and the trigger inputs of the BioSemi USB receiver.

http://www.cedrus.com/stimtracker/

[Lloyd]

StimTracker is nice when you need photocell or audio trigger sensing. This may be useful for timing testing purposes or because you have no other way to associate trigger port output with a visual or auditory stimuli because you are not using a purpose built experimental control program like Presentation, which provides direct access to triggering ports. I am not knocking StimTracker. We sell it, and it is great for some things, but to my knowledge, Cedrus does not guarantee timing accuracy or consistency when using the USB/serial input.

As such, I would caution you to be sure that the delay and jitter of the StimTracker USB/serial output and conversion to parallel TTL are sufficiently short and consistent for your application. I have had a StimTracker for several years and I have never considered using it as a USB to parallel converter because the developer specifically cautioned me against relying on the timing relationship between USB/serial input and parallel TTL output. This is consistent with USB connected devices in general. As a result, I have never tested this interface, but I will do so and report back to this thread.

A less expensive alternative to the StimTracker for if you are using NeuroBehavioral Systems Presentation with ActiveTwo is our new USB to parallel trigger converter. It uses NI-DAQmx drivers and specialized NI hardware to eliminate the delay and jitter normally associated with USB connected devices. I have compared this device to an ExpressCard parallel port and a PCIe parallel port, and found the delay to be less than 1 msec and jitter to be on the order of 0.1 msec under Windows 7 64-bit. Contact us at www.cortechsolutions.com if interested in this alternative.

[Lloyd]

I spent quite some time today digging into how to get parallel event output from Presentation via StimTracker's USB virtual serial port, but I was unsuccessful. The NeuroBS Wiki at http://www.neurobs.com/wiki/Presentatio ... timTracker indicates support for the initialization commands has been implemented in Presentation. I did have to change the com port number from COM33 to COM2 in Device Manager for Presentation to let me select it in the Ports tab. However, even after doing that and setting the init sequence and code sequence, I was unable to get it to recognize the events from Presentation's Test screen. The pinout for the DB 25 is here http://cedrus.com/support/stimtracker/t ... 0_pins.htm. I used pin 2 on the upper DB25 for signal and pin 25 for ground. I checked first with an oscilloscope, but did not see anything. Cedrus support said that the blue marker LED on the front of StimTracker should light up when an event is set on the port, but I never saw that when using the Test function in Presentation. Cedrus indicated that the problem may be with the programming of my StimTracker, but to program the StimTracker I would either need to write code incorporating their commands from http://www.cedrus.com/support/stimtrack ... mmands.htm or I could rely on code written by someone else (Presentation). So, stuck between a rock and a hard place here. It is possible my StimTracker is broken, but photocells and audio work fine, so I doubt it. I will post the same thread to Presentation's forum, but if anyone else has solved thsi problem, let us know.

[jmridge]

Hi,

Probably a simple question, but as my lab is upgrading their computers to models without parallel ports would this parallel port be suitable for the purpose of sending triggers or does anyone know of a better alternative?

Cheers

http://www.ebay.com/itm/Parallel-Port-D ... 0988778068