I'm developing some C++ code to synchronise data from a BioSemi and an EyeLink 1000 eye tracker using the tcp/ip servers of both systems.
When doing the same involving a NeuroScan (Scan 4.5), there was a useful option to run a simulator amplifier that pumped out sine wave data. Is it possible to set up the same type of feature in ActiView? Basically, I'd like to be able to generate data with known parameters without having to be connected to any amplifier.
Thanks for any help.
Ronan
Simulator option for ActiView?
-
Coen
- Site Admin
- Posts: 1148
- Joined: Fri Mar 26, 2004 7:00 pm
- Location: Amsterdam, Netherlands
- Contact:
When using the Eyelink in combination with the ActiveTwo, we recommend to use the Eyelink Analog Card (http://www.sr-research.com/accessories_ ... ncard.html) in combination with the BioSemi Analog Input Box (http://www.biosemi.com/aib.htm). This setup will eliminate timing problems between the Eyelink data and ActiveTwo data (because all data is sampled synchronously by the ActiveTwo while the Eyelink output card ensures constant delay).
Synchronizing the data from Eyelink and ActivTwo using TCL/IP servers is a huge task. You will need time stamps in both data streams, and then you will have to interlace the two data streams properly. The process is complicated because of the different and varying delays of both streams, and the different sample rates of the streams.
ActiView is an open source program written in LabVIEW, and fairly easily modified to show self-generated data. ActiView works by reading data from a ringbuffer, where the ringbuffer is constantly filled with ActiveTwo data by the USB driver functions. Replacing the ringbuffer by an array with artificially generated signals (use LabVIEW wave generation functions to fill the array), and changing ActiView to constantly circle this array with the right speed, will allow to test with self-generated data.
Best regards. Coen (BioSemi)
Synchronizing the data from Eyelink and ActivTwo using TCL/IP servers is a huge task. You will need time stamps in both data streams, and then you will have to interlace the two data streams properly. The process is complicated because of the different and varying delays of both streams, and the different sample rates of the streams.
ActiView is an open source program written in LabVIEW, and fairly easily modified to show self-generated data. ActiView works by reading data from a ringbuffer, where the ringbuffer is constantly filled with ActiveTwo data by the USB driver functions. Replacing the ringbuffer by an array with artificially generated signals (use LabVIEW wave generation functions to fill the array), and changing ActiView to constantly circle this array with the right speed, will allow to test with self-generated data.
Best regards. Coen (BioSemi)
Hi Coen,
Many thanks for prompt response and detailed advice.
Yes. I am only too aware of the complexity of the server approach. My problem is that I'm having to adapt software that already worked this way with NeuroScan.
At least the solution you suggest is a good fall back if my coding efforts fail.
Thanks again,
Ronan
Many thanks for prompt response and detailed advice.
Yes. I am only too aware of the complexity of the server approach. My problem is that I'm having to adapt software that already worked this way with NeuroScan.
At least the solution you suggest is a good fall back if my coding efforts fail.
Thanks again,
Ronan