.. _userDevicesAxoPatch:
    
AxoPatch Devices
================

This device supports the use of the AxoPatch 200 amplifier. It requires a :ref:`DAQ device <userDevicesNiDAQ>` to record from and output to each of the channels on the device. The following features are supported for the AxoPatch 200:
    
* Support for use with :ref:`Patch module <userModulesPatch>` and :ref:`Task Runner module <userModulesTaskRunner>`.
* Assisted switching between recording modes. The AxoPatch 200 uses a manual switch to select between current- and voltage-clamp recording modes. When a module requires access to a specific recording mode, a dialog window pops up instructing the experimenter to set the clamp mode accordingly.
* Manages separate holding levels for current- and voltage-clamp modes; automatically selects correct holding value when switching between modes.
* Records from the **gain** channel on the amplifier and automatically scales electrode data accordingly. 
* Records **LFP** channel output as meta-data of electrode recordings.

Hardware configuration
----------------------

At a minimum, using AxoPatch devices under ACQ4 requires:
    
* DAQ analog inputs connected to the Mode, Gain, and ScaledSignal outputs on the AxoPatch
* A DAQ analog output connected to the command input on the AxoPatch

Optionally, the LFP output on the AxoPatch may be connected to a DAQ analog input.

Configuration Options
---------------------

The following is an example :ref:`device configuration <userConfigurationDevices>` for an AxoPatch 200 device:

::

    AxoPatch200:
        driver: 'AxoPatch200'
        ModeChannel: 
            device: 'DAQ' 
            channel: '/Dev1/ai13'
            type: 'ai'
        GainChannel: 
            device: 'DAQ' 
            channel: '/Dev1/ai14'
            type: 'ai'
        LPFChannel: 
            device: 'DAQ' 
            channel: '/Dev1/ai15'
            type: 'ai'
        Command: 
            device: 'DAQ' 
            channel: '/Dev1/ao0'
            type: 'ao'
        ScaledSignal: 
            device: 'DAQ' 
            channel: '/Dev1/ai5'
            type: 'ai'
        icHolding: 0.0*pA
        vcHolding: -50*mV

The supported configuration parameters are:
    
* **driver** must be 'AxoPatch200'
* :ref:`DAQ channel specifications <userDevicesDAQGenericChannelSpecification>` for each of the AxoPatch channels that are connected to the DAQ:
    * **ModeChannel**: channel connected to the Mode output.
    * **GainChannel**: channel connected to the Gain output.
    * **LFPChannel**: channel connected to the LFP output.
    * **Command**: channel connected to the Command input.
    * **ScaledSignal**: channel connected to the Scaled Signal output.
* **icHolding**: The default holding current when the device is in current-clamp mode.
* **vcHolding**: The default holding voltage when the device is in voltage-clamp mode.
    
    
Manager Interface
-----------------

If an AxoPatch device is configured properly, a simple interface will appear in the :ref:`manager module <userModulesManager>` window:

    .. figure:: images/AxoPatch_ManagerInterface.png

This interface allows the recording mode and holding values for current- and voltage-clamp to be configured. Any changes made to these values will immediately affect the state of the device.


Task Runner Interface
---------------------

The TaskRunner interface for AxoPatch devices appears as a dock in the :ref:`Task Runner module <userModulesTaskRunner>` when a AxoPatch device is selected in the :ref:`device list <userModulesTaskRunnerSettings>`. This interface allows the design of stimulation waveforms and recording parameters for executing tasks. 

    .. figure:: images/AxoPatch_TaskInterface.png

The left half of this interface consists of three main sections:
    
* A list of operating modes (V-Clamp, I=0, I-Clamp Fast, I-Clamp Normal, Track). Running the task will require that the amplifier be set to the selected mode. If it is not, then a dialog will appear when the task starts, asking the user to set the mode accordingly.
* Controls affecting recording from the primary output channel of the amplifier (Scaled Signal). 
* Controls that determine the command output:
    * **Pre-set** sets the voltage or current command immediately before the task begins, if the box is checked.
    * **Holding** determines the voltage or current command that will be set immediately *after* the task finishes. If the box is unchecked, then the current holding value (as indicated in the Manager interface described above) will be used.
    * A :ref:`function generator <userInterfacesFunctionGenerator>` that is used to specify the output waveform and sequence parameters.

The right half of the interface holds :ref:`plot areas <userInterfacesGraphics>` for displaying the recorded signal (top) and command signal (bottom).

Stored data format
------------------

AxoPatch tasks that store to disk will generate a single :ref:`MetaArray file <userMetaArrayFiles>` containing two columns: "command" and "primary". Metadata are as follows:
    
* All :ref:`DAQ configuration settings <userDevicesNiDAQStorage>` including sample rate, filtering, and downsampling.
* The AxoPatch operating mode (V-Clamp, I=0, I-Clamp Fast, I-Clamp Normal, Track).
* Current Gain and LFP settings.
* The standard :ref:`function generator metadata structure <userInterfacesFunctionGeneratorStorage>`.