Open Ephys Interface

Available on macOS

Description

Interface to the Open Ephys GUI application. Requires an Open Ephys Event Broadcaster module listening on the specified hostname and port.

The primary function of this component is to compute the offset between the Open Ephys and MWorks clocks. To enable this, your experiment must send periodic synchronization words to TTL inputs on the Open Ephys acquisition board. Although this component does not send the synchronization signals itself, it must be made aware of them via the sync and sync_channels parameters.

Additionally, this component can receive information on spikes detected by an Open Ephys Spike Detector or Spike Sorter module. (Note that the Event Broadcaster must appear after the spike detection module in the signal chain.)

Signature

iodevice/open_ephys_interface

Required Parameters

hostname

Examples

localhost

dicarlo-open-ephys-12.mit.edu

Hostname of the computer running the Open Ephys GUI

port

Example

5557

TCP port used by the Event Broadcaster module

sync

Variable from which to read synchronization words sent to TTL inputs on the Open Ephys acquisition board. Assigning to the variable should also initiate transmission of the TTL signals (e.g. by associating it with a digital output channel on another Input/Output device).

sync_channels

Examples

0,1

4:7

1,4:6,7

TTL input channels on the Open Ephys acquisition board to which synchronization words are sent. The first channel should receive the least significant bit, the last channel the most significant.

Optional Parameters

clock_offset

Variable in which to store computed offsets between the Open Ephys and MWorks clocks. Dividing an Open Ephys time (i.e. sample number) by the sampling rate and adding this offset (reported in microseconds) yields the corresponding MWorks time.

spikes

Variable in which to store information on detected spikes.

For every spike event it receives from Open Ephys, MWorks will assign a new value to this variable. The value will be a dictionary with the following fields:

oe_timestamp

Timestamp on Open Ephys clock (i.e. sample number)

sorted_id

Sorted unit ID (or 0 if unsorted)

electrode_id

Electrode ID

channel

Channel in which threshold crossing was detected (relevant only for stereotrodes and tetrodes)

The MWorks timestamp on the value (i.e. the time recorded in the event file) will be the Open Ephys timestamp converted to MWorks’ clock (using the computed clock offset). This enables direct comparison of spike times with the times of other events.

autostart

Default

NO

If YES, the device will start I/O automatically (as if by an implicit Start IO Device action) when the experiment starts running.

Note: Device I/O will always stop automatically when the experiment stops running, irrespective of this setting.

alt

Alternative device to use if this one fails to initialize (e.g. because the required hardware is not available). If #allowAltFailover is set to 0 or false, this parameter is ignored.

Placement

Allowed at top level:	Yes
Allowed parent:	Folder