Connecting or disconnecting the breakout board while the PC is on causes damage to the
-FMChost. For more details, see Breakout Board Guide.
+
Read the following warnings before starting to work with your system. These
+are crucial aspects to consider during setup and usage that are included in
+the documentation but are listed here for your convenience.
+
Read the complete documentation carefully to understand how the system works
+and refer back to these warnings before using it.
-
-
Warning
-
Power off the PC before connecting/disconnecting the breakout board.
-
-
Headstage voltage must be configured correctly for operation. The voltage that works
-for one headstage can damage another, and depends on your hardware configuration such
-as tether length. For more details, see Tethered Headstage Voltages.
Ensure each headstage is configured with the correct voltage according to its
-specification before connecting and switching on the headstage port switch.
+
Connecting or disconnecting the Breakout Board while the PC is on
+can damage to the PCIe Host. For more details, see
+Breakout Board Guide. Power off the PC before connecting/disconnecting the
+breakout board.
For the current Bonsai.ONIX library which is being revised to improve usability
-
-
Headstage port voltage configuration is managed via the ONIContext node
-or the HeadstagePortControlDevice node. The changes you make using these
-nodes apply immediately and persist in hardware even if the Bonsai workflow is not
-running. Headstage port voltage is reset to the default 4.9V only on a power cycle
-(power off and on — not reboot).
-
-
-
Warning
-
Keep the headstage port switches off until you have configured each port correctly.
-
-
-
Warning
-
Remember to set the headstage voltage to the desired value after a power cycle.
-
-
-
The ONIContext provides a dynamic window to read and write to hardware,
-but parameters such as device voltage are not saved in the node when the workflow is
-saved. The HeadstagePortControlDevice node also reads and writes to hardware,
-but parameters are saved with the workflow. On loading a workflow, Bonsai writes the
-parameter values set when the workflow was last saved.
-
-
-
Warning
-
When you configure the voltage, the ONIContext node shows that value
-and when you save the workflow this value is not saved. Therefore, that value will
-not be set to hardware when you load the workflow again. On loading the workflow,
-the ONIContext node will be reading the voltage that is already set
-on the hardware and showing this in the LinkVoltage field.
-
-
-
Warning
-
When you configure the voltage, the HeadstagePortControlDevice node shows
-that value and when you save the workflow this value is saved. Therefore, that value
-will be set to hardware when you load the workflow again. If you make changes to the
-voltage value (with any node) and save the workflow, they will be saved in the
-LinkVoltage property of the HeadstagePortControlDevice node.
Check that the voltage set to the headstage port is correct for the
-Neuropixels-1.0e Headstage by using a workflow of a single ONIContext
-node to configure it before connecting the headstage in order to open a workflow that
-contains the NeuropixelsV1eDevice node.
-
-
-
An ONIContext node or any device node in a workflow can override device
-settings in another workflow if device addresses are not distinct, because these nodes
-read/write directly to hardware.
Ensure each headstage is configured with the correct voltage. Although
+headstages are quite tolerate of over-voltage and under-voltage conditions,
+they are only guaranteed to function within a specified range. When using
+long and/or thin tethers, the voltage drop across the cable can become
+significant. For more details, see Headstage Voltages.
ONIX is a data acquisition system for neuroscience, composed of various pieces
-of hardware. ONIX differs from other acquisition systems in three major points:
There is a growing appreciation of experiments that examine the natural
behaviours of animals. This often means using larger and more intricate
(perhaps 3D) experimental setups. It also means that the animal should be
impaired as little as possible by the recording setup. To achieve this it is of
course important to reducing the weight of the headstage, but the weight of the
tether that connects the headstage to the acquisition system is often
-overlooked. As the animal explores the arena, the centre of mass of the tether
+overlooked. As the animal explores the arena, the center of mass of the tether
is rarely directly above the animal. Instead, it is off to one side,
-introducing a rotational force on the animal. The animal must compensate for
-this torque in order to keep its head up straight. Because the ONI
-specification allows communication over a single wire, ONIX uses a single
+introducing a rotational force (torque) on the animal. The animal must
+compensate for this torque in order to keep its head up straight. Because the
+ONI specification allows communication over a single wire, ONIX uses a single
coaxial cable, making ONIX tethers lighter and thinner compared to classic
acquisition systems. ONIX tethers are 0.1 to 0.4 mm in diameter and are
extremely flexible.
In closed-loop experiments, data is not only acquired, but also processed and
acted upon. For instance, one can provide optogenetic stimulation to a brain
area every time a certain type of event is detected by an extracellular probe.
The closed-loop latency of the acquisition system describes how much time
-passes between the initial event and the response of the system. In classic
-acquisition systems, this time is primarily spent on transmitting and
-processing acquired data, which becomes more and more challenging as the number
-of channels on a probe increases. A short latency allows the user to respond on
-the timescale of the biological event; for instance, within the integration
-window of a neuron.
-
Many classic acquisition systems rely on a USB connection between the
-acquisition board and PC. The slower transfer characteristics of USB means that
-a typical closed-loop latency would be in the range of several to tens of
-milliseconds. This is a considerable duration for the brain, as it is notably
-longer than the average action potential duration of around 1 ms. ONIX has much
-shorter latencies, of around 150 microseconds, because the host board of ONIX
-is directly connected to the acquisition PC, in a PCIe slot. This means that
-the system can respond quickly to detected events. It also means that time is
-freed up for this detection itself; by reducing the overhead time, more complex
-analysis can be run to extract the phenomenon you are interested in.
+passes between the physical event and the response of the real-time system. A
+short latency allows the user to respond on the timescale of the biological
+event; for instance, within the integration window of a neuron.
+
Many acquisition systems rely on a USB connection between the acquisition board
+and PC. Or, they rely on closed-source 3rd-party drivers and APIs that are not
+optimized for low response latencies. The slower transfer characteristics of
+USB means that a typical closed-loop latency is in the range of several
+to tens of milliseconds. This is a considerable duration for the brain, as it
+is notably longer than the average action potential duration of around 1 ms. On
+average, ONIX provides much shorter latencies, of around 150 microseconds, because:
+
+
ONIX is transfers data to the host computer without the CPU via DMA over PCIe.
+
ONIX uses a custom device driver optimized for low latency.
+
The ONI API allows explicit control over a single parameter to governs the
+trade off between data latency and overall bandwidth.
+
+
This permits the user to optimize their system’s response time for a given
+experiment. In all, this means that the system can respond quickly to detected
+events. It also means that time is freed up for this detection itself; by
+reducing the overhead time, more complex analysis can be run to extract the
+phenomenon you are interested in.
Active, near-zero torque commutators to prevent tether twisting during
-freely moving recordings with headstages and/or miniscopes.
-This page provides a very brief overview of the commutators; for a more extensive
-walkthrough, please follow the documentation link for Commutators.
+
Active, near-zero torque commutators prevent tether twisting during freely
+moving recordings with headstages and/or miniscopes. This page provides a very
+brief overview of the commutators; for a more extensive walkthrough, please
+follow the documentation link for Commutators.
ONIX uses an active commutator to prevents tether twisting during freely moving
recordings. A inertial measurement unit (IMU) on the headstage or miniscope
sends orientation data to the host computer. Because the real-time orientation
-of the animal is known, software (e.g. Bonsai) can be used to send commands to
-the commutator via its USB interface, and the motor in the commutator will turn
-when the animal does. A high-quality radio-frequency rotary joint inside the
-commutator maintains electrical connectivity for both power and high-frequency
-data signals between the tether leading to the headstage and the coaxial cable
+of the animal is known, software can be used to send commands to the commutator
+via its USB interface, and the motor in the commutator will turn when the
+animal does. A high-quality radio-frequency rotary joint inside the commutator
+maintains electrical connectivity for both power and high-frequency data
+signals between the tether leading to the headstage and the coaxial cable
leading to the PCIe host board while turning.
The FMC Host Link Controller is used to control and monitor DS90UB9x-based
serialized connections to hubs connected to a host such as headstages and
-miniscopes. It can control power provided to those hubs and receives RF lock,
-CRC error, and other information.
+miniscopes. It can control the voltage provided to those hubs and receives RF
+lock, CRC error, and other diagnostic information.
Note
Typical inplementaitons will default link voltages to 0. Often the link
diff --git a/Hardware Guide/Datasheets/heartbeat.html b/Hardware Guide/Datasheets/heartbeat.html
index 08fb897f..7042bb3a 100644
--- a/Hardware Guide/Datasheets/heartbeat.html
+++ b/Hardware Guide/Datasheets/heartbeat.html
@@ -30,7 +30,7 @@
-
+
@@ -381,6 +381,7 @@
The RHS2116 Headstage is a serialized headstage for small animals with 32 channels which can independently be configured as stimulator outputs or amplifier inputs. The RHS2116 can be used with passive probes (e.g. silicon arrays, EEG/ECOG arrays, etc) using a 36-Channel Omnetics EIB. To learn how to use the RHS2116 headstage in software, refer to the RHS2116Device software guide. For technical information, refer to the RHS2116 datasheet.
-
-
Warning
-
There are multiple headstage hardware revisions. The revision number is printed on the PCB. You can use the compatibility matrix to find host hardware for your headstage.
-
+
The RHS2116 Headstage is a serialized headstage for small animals with 32
+bi-direcional channels which each can be used to deliver electrical stimuli.
+The RHS2116 Headstage can be used with passive probes (e.g. silicon arrays, EEG/ECOG
+arrays, etc) using a 36-Channel Omnetics EIB.
*Do not exceed 5.0 VDC at the coaxial input to the headstage.
+Make sure you make this measurement at the headstage (see
+Measuring Headstage Voltage) to account for a potential voltage drop in the
+tether.
Note
-
Have a look at the Making Coaxial Tethers page for more details on micro-coax headstage tethers
+
Have a look at the Making Coaxial Tethers page for more details on micro-coax
+headstage tethers
RHS2116 headstage uses two 16-channel Intan RHS2116 bioamplifier chip. The chip is operated at a fixed
-sampling rate of 30 kHz/channel. These 32 ephys channels are exposed via a 36 pin Omnetics connector at the edge of the headstage and can record from most passive probes (e.g. tetrodes, silicon probe arrays, tungsten microwires, steel EEG wires, etc.) as well as stimulate.
Configure the RHS2116Device node properties and run the workflow on the RHS2116Device page if you want to collect data
-
Configure the RHS2116TriggerDevice node properties and run the workflow on the RHS2116TriggerDevice page if you want to trigger stimulus
-
-
Stimulus trains can be parameterized in a similar way to the master-8 or pulse pal. Refer to the Configuration GUI section of the documentation for more info.
-
-
-
-
-
-
+sampling rate of ~30 kHz/channel. These 32 ephys channels are exposed via a 36
+pin Omnetics connector at the
+edge of the headstage and can record from most passive probes (e.g. tetrodes,
+silicon probe arrays, tungsten microwires, steel EEG wires, etc.) as well as
+stimulate.
Connect the headstages either directly to host or through the breakout board (see Headstage Link).
-
The LED on the breakout board (and the PCIe board itself, if visible) should turn purple when the link is made between the headstage and the PCIe host board.
-
Double-clicking on the OniContext node in Bonsai should now show an additional tab, labelled with the type of headstage.
+
Connect the headstage to one of the Ports on the Breakout Board by screwing
+in the SMA connector. Alternatively, the headstage can be pluged directly
+into port A or B on the PCIe control board using an SMA to MMCX adapter (see
+Headstage Link).
The voltage on the headstage must be carefully regulated: if its too low the
-headstage will not function reliably. If the voltage is too high sensitive
-components could be damaged. Many issues with the system can be traced back to
-inadequate headstage voltage supply.
Each ONIX headstage has a required operating voltage that is specified on its
+documentation page. Because ONIX hardware supports headstages that have
+different voltage requirements, it must be changed to match the requirements
+of the headstage that is plugged into a port. If the headstage voltage is too
+low, it will not function reliably. If the voltage is too high, the headstage
+will dissipate excess heat and it may be damaged.
Each headstage has a minimum and maximum voltage requirement (e.g. 5.3 to 5.7
-Volts for Headstage-64) circuits on the board to function properly. If
-the voltage is far too low, the green LED on the headstage will be dim and
-Bonsai will not detect the headstage. Even if the LED is bright, a borderline
+
The headstage voltage is set using FMC Link Controller devices
+on the PCIe Host. Each headstage has a minimum and maximum voltage
+requirement (e.g. 5.3 to 5.7 Volts for Headstage-64) in order for
+circuits on the board to function properly. If the voltage is far too low, the
+host computer will not be able to detect the headstage. A borderline
voltage can still cause connectivity issues as the headstage occasionally dips
-beneath the power it needs to function properly.
-
-
The voltage output at the FMC-host can be set in Bonsai:
-
-
-
Default headstage voltage is 4.9 V
+below the level it needs to function properly.
+
+
Attention
+
The OpenEphys.Onix1 Bonsai package automatically sets the
+headstage port voltage by default, but allows the user to override the
+voltage setting as well. The documentation linked shows how to use this
+functionality and what valid voltage ranges are for each headstage. This
+functionality has been been tuned for the tethers that are shipped with each
+headstage. The voltage override is available when custom tethers are used
+(see Measuring Headstage Voltage).
-
-
-
Increasing the voltage to 7V in Bonsai (measured as 5V at the headstage) allows the second headstage to connect.
-
-
The voltage set in Bonsai is not identical to the voltage supplied to the
-headstage, as some voltage drop will occur over the coaxial cable tether that
-connects them. The amount of voltage drop will depend on the cable properties
-(e.g. thickness) and even the temperature of the cable. These very thin tethers
-can cause large voltage drops, so that even when the voltage setting in Bonsai
-seems high, the headstage is only seeing 3 or 4 Volts and becomes unreliable.
-Voltage should therefore always be measured on the headstage itself. The
-voltage setting is persistent until computer power off. It gets stored in the
-hardware, so even after a reboot, it will be set to the latest value.
+
The voltage set in software is not identical to the voltage supplied to the
+headstage, as some voltage drop will occur over the tether that connects them. The
+amount of voltage drop is proportional to the current draw of the headstage and
+inversely proportional to the thickness of the tether. The thin tethers used
+with ONIX headstages can result in significant voltage drops that need to be
+compensated for. For very long (5 to 10m) and thin (diameter of 0.2mm) coaxial
+tethers, the voltage drop can be on the order of 2 volts. For this reason, the
+headstage voltage must be measured on the headstage itself.
If you have slowly increased the voltage supplied to a headstage, but it does
-not appear as a tab in the ONI-Context, try turning the voltage supply to 0 and
-back to the higher value before refreshing the ONI-Context.