Search found 1121 matches

by Coen
Wed Feb 14, 2024 2:42 pm
Forum: BioSemi Software (ActiView executable)
Topic: Editing 32-channels in default.cfg
Replies: 3
Views: 91

Re: Editing 32-channels in default.cfg

Do not edit CFGs in Notepad.

Open ActiView, set the controls according to your preferences, make a short data file, select the "about" tabpage and save your front-panel settings in a new CFG.

Best regards, Coen (BioSemi)
by Coen
Wed Feb 14, 2024 2:37 pm
Forum: BioSemi all other topics
Topic: Use few electrodes than64
Replies: 2
Views: 99

Re: Use few electrodes than64

No, best regards, Coen (BioSemi)
by Coen
Tue Nov 07, 2023 2:47 pm
Forum: BioSemi Hardware
Topic: Biosemi simultaneous Biopac
Replies: 1
Views: 3240

Re: Biosemi simultaneous Biopac

Why don't you measure simultaneous EEG and ECG (extra TP-flat electrodes) with the BioSemi system ?

Best regards, Coen (BioSemi)
by Coen
Tue Oct 31, 2023 3:11 pm
Forum: EEG data analysis
Topic: How Can I Verify That ActiveTwo USB-Receiver 5.1 Is Receiving Triggers from PsychoPy 3?
Replies: 4
Views: 4645

Re: How Can I Verify That ActiveTwo USB-Receiver 5.1 Is Receiving Triggers from PsychoPy 3?

Select the "analog" trigger format and trigger line 1-16 are displayed as colored dots/bars. Select the "decimal" trigger format and the triggers are displayed as two groups of 8 bit numbers.
by Coen
Fri Oct 20, 2023 12:52 pm
Forum: BioSemi all other topics
Topic: ActiView TCP server
Replies: 11
Views: 13894

Re: ActiView TCP server

Filtering the TCP outputs is not a standard option in ActiView, it is only possible by modifying the (open source LabVIEW) code. You could consider programming a simple low pass in you C++ client. High frequency interference on the photo sensor signal is usually caused by 100 Hz fluctuating light fr...
by Coen
Tue Oct 10, 2023 7:32 pm
Forum: BioSemi Hardware
Topic: Sending triggers from Response Switch through parallel port to psychopy
Replies: 3
Views: 4720

Re: Sending triggers from Response Switch through parallel port to psychopy

You have to make a suitable cable to route pins 17+18 of the USB-receiver to readable pins of the psychopy PC.

Best regards, Coen (BioSemi)
by Coen
Tue Oct 03, 2023 5:37 pm
Forum: BioSemi all other topics
Topic: ActiView TCP server
Replies: 11
Views: 13894

Re: ActiView TCP server

The timing across the channels is only determined by the sampling moments. All ADCs (EEG and sensors) in the AD-box sample at the same moment, controlled by the same clock pulse (sampling is synchronous within 10 picosecond). The trigger channel is added in the USB-receiver with a precision of one s...
by Coen
Mon Sep 25, 2023 4:00 pm
Forum: BioSemi all other topics
Topic: Trouble with repairing BDF file
Replies: 8
Views: 7426

Re: Trouble with repairing BDF file

We have inspected the file, all the data (not just the triggers) is corrupted after 1960 seconds (total file is 4576 sec). In an Hex-file-editor, we can see that after 1960 seconds the data is from an Excel file. It looks like hard disk problems, but how this could happen without error popups is puz...
by Coen
Mon Sep 25, 2023 3:29 pm
Forum: BioSemi all other topics
Topic: ActiView TCP server
Replies: 11
Views: 13894

Re: ActiView TCP server

The photosensor does not output negative values. You can connect a signal generator to the ERGO (see https://www.biosemi.nl/forum/viewtopic.php?f=1&t=931&p=2854 ). Even easier is to connect a potentiometer (approx. 10k linear) between pin 1 and 3 with the wiper to pin 4 and pin 5 to pin 2 (ERGO will...
by Coen
Mon Sep 25, 2023 2:38 pm
Forum: BioSemi all other topics
Topic: Trouble with repairing BDF file
Replies: 8
Views: 7426

Re: Trouble with repairing BDF file

It appeared that the header and part of the data at the beginning of the file were missing (we have no idea how the file could get corrupted like this, we have never seen anything similar). We could repair the file by stripping the begin of the file until the start of a whole 1 sec data block, addin...
by Coen
Thu Sep 21, 2023 9:41 pm
Forum: BioSemi Hardware
Topic: Sending triggers from Response Switch through parallel port to psychopy
Replies: 3
Views: 4720

Re: Sending triggers from Response Switch through parallel port to psychopy

With "RespSwitch=1" in the CFG, the button triggers are available on pins 17 and 18 of the trigger port on the USB-receiver, see https://www.biosemi.com/faq/trigger_signals.htm . I understand that you acquire the psychopy triggers with the AIB. Why don't you connect the psychopy triggers directly to...
by Coen
Thu Sep 21, 2023 2:32 pm
Forum: BioSemi all other topics
Topic: Trouble with repairing BDF file
Replies: 8
Views: 7426

Re: Trouble with repairing BDF file

The first bytes of the header are already corrupted, and it looks like a lot of fields have been overwritten with zero's. We have only seen things like that when a computer crashes during recording (although usually in such cases only the file length field is wrong and can be easily repaired). Pleas...
by Coen
Thu Sep 21, 2023 2:03 pm
Forum: BioSemi Software (ActiView executable)
Topic: Acquisition software SDK support for ARM platforms
Replies: 1
Views: 5152

Re: Acquisition software SDK support for ARM platforms

The ARM processor is not supported by BioSemi. The driver source code is proprietary and not made available to BioSemi users. The best way to proceed is to set up an extra thread in (open source LabVIEW) ActiView to read data from the ringbuffer (example code is available). The extra thread runs par...
by Coen
Wed Sep 20, 2023 9:16 pm
Forum: BioSemi Software (ActiView executable)
Topic: EEG and posturography collection
Replies: 1
Views: 2775

Re: EEG and posturography collection

It is possible to start recording with a TTL pulse, see https://www.biosemi.nl/forum/viewtopic.php?f=2&t=711&p=2174 . However, this is not precise enough and not sufficient for synchronization. For synchronization, TTL timing pulses should be sent from BioSemi to posturography (similar to https://ww...
by Coen
Thu Sep 14, 2023 2:18 pm
Forum: BioSemi Software (ActiView executable)
Topic: strange artifact across all sites in EEG
Replies: 2
Views: 3244

Re: strange artifact across all sites in EEG

60 Hz in a shielded booth means interference by magnetic field. Bundle and twist the electrode wires to minimize enclosed loops.

Best regards, Coen (BioSemi)
by Coen
Thu Sep 14, 2023 2:13 pm
Forum: BioSemi all other topics
Topic: Trouble with repairing BDF file
Replies: 8
Views: 7426

Re: Trouble with repairing BDF file

It looks like most of the header is zero. It is unlikely that this is a BDF file generated by ActiView. Which error message does ActiRead display ?

Best regards, Coen (BioSemi)
by Coen
Thu Sep 07, 2023 1:42 pm
Forum: BioSemi all other topics
Topic: ActiView TCP server
Replies: 11
Views: 13894

Re: ActiView TCP server

The above is correct. The ADCs output 24-bit data words. The USB-receiver convert these words into 32 bit integers by just adding a least significant zero byte. ActiView processes these 32-bit integers, but only the 3 most significant bytes are streamed to BDF file and sent via TCP/IP. The only proc...
by Coen
Wed Sep 06, 2023 5:40 pm
Forum: BioSemi all other topics
Topic: ActiView TCP server
Replies: 11
Views: 13894

Re: ActiView TCP server

What is sent by TCP/IP are the 3 most significant bytes of a signed 32 bit integer. The client should again construct the signed 32 bit integer from these 3 bytes (add a zero least significant byte). The MSB of the most significant byte is the sign bit.

Best regards, Coen (BioSemi)
by Coen
Tue Aug 22, 2023 5:46 pm
Forum: BioSemi Software (ActiView executable)
Topic: Strange Signal Drift
Replies: 1
Views: 2934

Re: Strange Signal Drift

Drifts like that are usually caused by perspiration. The sweat disturbs the skin-gel-electrode interface. Try to maintain a comfortable cool environment for the subject. Be careful with fans because electric motors close to the subject may cause interference.

Best regards, Coen (BioSemi)
by Coen
Wed Jul 19, 2023 5:44 pm
Forum: BioSemi Software (ActiView executable)
Topic: Irregular noise all over
Replies: 4
Views: 4317

Re: Irregular noise all over

You probably added so much gel that there was a gel bridge between CMC and DRL (40 dB less CMRR). Apply just enough gel to fill the holder, but not more. Use the tip of the syringe to work the gel between the hair. Offsets should be between approx. +100 mV and -100 mV and stable. If within this rang...
by Coen
Thu Jul 13, 2023 11:14 pm
Forum: BioSemi all other topics
Topic: Relabel triggers in .bdf file
Replies: 1
Views: 3205

Re: Relabel triggers in .bdf file

There are no trigger labels in the BDF file.

Best regards, Coen (BioSemi)
by Coen
Fri May 12, 2023 1:28 pm
Forum: BioSemi Hardware
Topic: Intermittent Blue Light issue
Replies: 1
Views: 3137

Re: Intermittent Blue Light issue

Broken wire conductors, see http://www.biosemi.com/faq/check_electrodes.htm . Send the electrode sets to BioSemi for checking and repair or replacement.

Best regards, Coen (BioSemi)
by Coen
Thu May 04, 2023 12:36 pm
Forum: BioSemi Hardware
Topic: Optical Sensors (Trigger)
Replies: 4
Views: 4940

Re: Optical Sensors (Trigger)

Purchase 2 Photo-Sensors (http://www.biosemi.com/accessoires.htm), send your AD-boxes to add the ERGO inputs. Use the USB trigger interface (http://www.biosemi.com/faq/USB%20Trigger%20interface%20cable.htm) to input the triggers to the USB-Receiver (http://www.biosemi.com/receiver.htm). The optic se...
by Coen
Wed May 03, 2023 1:13 pm
Forum: BioSemi Hardware
Topic: Optical Sensors (Trigger)
Replies: 4
Views: 4940

Re: Optical Sensors (Trigger)

Please describe the setup: which triggerbox and how is it connected to the amplifier and optical sensors ?

Best regards, Coen (BioSemi)
by Coen
Thu Apr 27, 2023 5:17 pm
Forum: BioSemi Hardware
Topic: Persistent connection issue with New USB2 Receiver (Win11)
Replies: 4
Views: 4725

Re: Persistent connection issue with New USB2 Receiver (Win11)

If I understand correctly, ActiveTwo acquisition and trigger generation run on the same computer, and both the USB-receiver and USB-trigger-interface connect inconsistently. The two USB devices work independent of each other. It is unlikely that both USB devices are defect, so I suspect a computer p...
by Coen
Thu Apr 27, 2023 3:38 pm
Forum: BioSemi Hardware
Topic: Persistent connection issue with New USB2 Receiver (Win11)
Replies: 4
Views: 4725

Re: Persistent connection issue with New USB2 Receiver (Win11)

The serial COM port is only used by the USB-->Parallel trigger interface (https://www.biosemi.com/faq/USB%20Trigger%20interface%20cable.htm), it has nothing to do with the USB receiver (https://www.biosemi.com/receiver.htm). Without the COM port active, the ActiveTwo system works and receives trigge...