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Device Node Tree

This chapter contains reference documentation for the settings and measurement data available on PQSC Instruments. Whilst Functional Description describes many of these settings in terms of the features available in the LabOne User Interface, this chapter describes them on the device level and provides a hierarchically organized and comprehensive list of device functionality.

Since these settings and data streams may be written and read using the LabOne APIs (Application Programming Interfaces) this chapter is of particular interest to users who would like to perform measurements programmatically via LabVIEW, Python, MATLAB, .NET or C.

Please see:

  • Introduction for an introduction of how the instrument's settings and measurement data are organized hierarchically in the Data Server's so-called "Node Tree".
  • Reference Node Documentation for a reference list of the settings and measurement data available on PQSC Instruments, organized by branch in the Node Tree.

Introduction

This chapter provides an overview of how an instrument's configuration and output is organized by the Data Server.

All communication with an instrument occurs via the Data Server program the instrument is connected to (see LabOne Software Architecture for an overview of LabOne's software components). Although the instrument's settings are stored locally on the device, it is the Data Server's task to ensure it maintains the values of the current settings and makes these settings (and any subscribed data) available to all its current clients. A client may be the LabOne User Interface or a user's own program implemented using one of the LabOne Application Programming Interfaces, e.g., Python.

The instrument's settings and data are organized by the Data Server in a file-system-like hierarchical structure called the node tree. When an instrument is connected to a Data Server, its device ID becomes a top-level branch in the Data Server's node tree. The features of the instrument are organized as branches underneath the top-level device branch and the individual instrument settings are leaves of these branches.

For example, the auxiliary outputs of the instrument with device ID "dev1000" are located in the tree in the branch:

/dev1000/auxouts/

In turn, each individual auxiliary output channel has its own branch underneath the "AUXOUTS" branch.

/dev1000/auxouts/0/
/dev1000/auxouts/1/
/dev1000/auxouts/2/
/dev1000/auxouts/3/

Whilst the auxiliary outputs and other channels are labelled on the instrument's panels and the User Interface using 1-based indexing, the Data Server's node tree uses 0-based indexing. Individual settings (and data) of an auxiliary output are available as leaves underneath the corresponding channel's branch:

/dev1000/auxouts/0/demodselect
/dev1000/auxouts/0/limitlower
/dev1000/auxouts/0/limitupper
/dev1000/auxouts/0/offset
/dev1000/auxouts/0/outputselect
/dev1000/auxouts/0/preoffset
/dev1000/auxouts/0/scale
/dev1000/auxouts/0/value

These are all individual node paths in the node tree; the lowest-level nodes which represent a single instrument setting or data stream. Whether the node is an instrument setting or data-stream and which type of data it contains or provides is well-defined and documented on a per-node basis in the Reference Node Documentation section in the relevant instrument-specific user manual. The different properties and types are explained in Node Properties and Data Types .

For instrument settings, a Data Server client modifies the node's value by specifying the appropriate path and a value to the Data Server as a (path, value) pair. When an instrument's setting is changed in the LabOne User Interface, the path and the value of the node that was changed are displayed in the Status Bar in the bottom of the Window. This is described in more detail in Exploring the Node Tree.

Module Parameters

LabOne Core Modules, such as the Sweeper, also use a similar tree-like structure to organize their parameters. Please note, however, that module nodes are not visible in the Data Server's node tree; they are local to the instance of the module created in a LabOne client and are not synchronized between clients.

Node Properties and Data Types

A node may have one or more of the following properties:

Property Description
Read Data can be read from the node.
Write Data can be written to the node.
Setting The node corresponds to a writable instrument configuration. The data of these nodes are persisted in snapshots of the instrument and stored in the LabOne XML settings files.
Streaming A node with the read attribute that provides instrument data, typically at a user-configured rate. The data is usually a more complex data type, for example demodulator data is returned as ZIDemodSample. A full list of streaming nodes is available in the Programming Manual in the Chapter Instrument Communication. Their availability depends on the device class (e.g. MF) and the option set installed on the device.
Pipelined If the sequence pipeliner mode is off the value set to the node is applied immediately. Otherwise, it goes to the staging area of the sequence pipeliner instead. Multiple pipelined nodes can be programmed as part of a job definition, that is finalized by writing a one to the relevant commit node.

A node may contain data of the following types:

Integer Integer data.
Double Double precision floating point data.
String A string array.
Integer (enumerated) As for Integer, but the node only allows certain values.
Composite data type For example, ZIDemodSample. These custom data types are structures whose fields contain the instrument output, a timestamp and other relevant instrument settings such as the demodulator oscillator frequency. Documentation of custom data types is available in

Exploring the Node Tree

In the LabOne User Interface

A convenient method to learn which node is responsible for a specific instrument setting is to check the Command Log history in the bottom of the LabOne User Interface. The command in the Status Bar gets updated every time a configuration change is made. Figure 1 shows how the equivalent MATLAB command is displayed after modifying the value of the auxiliary output 1's offset. The format of the LabOne UI's command history can be configured in the Config Tab (MATLAB, Python and .NET are available). The entire history generated in the current UI session can be viewed by clicking the "Show Log" button.

Figure 1: When a device's configuration is modified in the LabOne User Interface, the Status Bar displays the equivalent command to perform the same configuration via a LabOne programming interface. Here, the MATLAB code to modify auxiliary output 1's offset value is provided. When "Show Log" is clicked the entire configuration history is displayed in a new browser tab.

In a LabOne Programming Interface

A list of nodes (under a specific branch) can be requested from the Data Server in an API client using the listNodes command (MATLAB, Python, .NET) or ziAPIListNodes() function (C API). Please see each API's command reference for more help using the listNodes command. To obtain a list of all the nodes that provide data from an instrument at a high rate, so-called streaming nodes, the streamingonly flag can be provided to listNodes. More information on data streaming and streaming nodes is available in the LabOne Programming Manual.

The detailed descriptions of nodes that is provided in Reference Node Documentation is accessible directly in the LabOne MATLAB or Python programming interfaces using the "help" command. The help command is daq.help(path) in Python and ziDAQ('help', path) in MATLAB. The command returns a description of the instrument node including access properties, data type, units and available options. The "help" command also handles wildcards to return a detailed description of all nodes matching the path. An example is provided below.

    daq = zhinst.core.ziDAQServer('localhost', 8004, 6)
    daq.help('/dev1000/auxouts/0/offset')
    # Out:
    # /dev1000/auxouts/0/OFFSET#
    # Add the specified offset voltage to the signal after scaling. Auxiliary Output
    # Value = (Signal+Preoffset)*Scale + Offset
    # Properties: Read, Write, Setting
    # Type: Double
    # Unit: V

Data Server Nodes

The Data Server has nodes in the node tree available under the top-level /zi/ branch. These nodes give information about the version and state of the Data Server the client is connected to. For example, the nodes:

  • /zi/about/version
  • /zi/about/revision

are read-only nodes that contain information about the release version and revision of the Data Server. The nodes under the /zi/devices/ list which devices are connected, discoverable and visible to the Data Server.

The nodes:

  • /zi/config/open
  • /zi/config/port

are settings nodes that can be used to configure which port the Data Server listens to for incoming client connections and whether it may accept connections from clients on hosts other than the localhost.

Nodes that are of particular use to programmers are:

  • /zi/debug/logpath - the location of the Data Server's log in the PC's file system,
  • /zi/debug/level - the current log-level of the Data Server (configurable; has the Write attribute),
  • /zi/debug/log - the last Data Server log entries as a string array.

The Global nodes of the LabOne Data Server are listed in the Instrument Communication chapter of the LabOne Programming Manual

Reference Node Documentation

This section describes all the nodes in the data server’s node tree organized by branch.

CLOCKBASE

/dev..../clockbase

Properties: Read
Type: Double
Unit: Hz

Returns the internal clock frequency of the device.

EXECUTION

/dev..../execution/enable

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Activate the trigger generation. Auto-resets to zero when done.

/dev..../execution/holdoff

Properties: Read, Write, Setting
Type: Double
Unit: s

Hold-off time between repeated triggers.

/dev..../execution/progress

Properties: Read
Type: Double
Unit: None

The fraction of the triggers generated so far.

/dev..../execution/repetitions

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Number of triggers to be generated.

/dev..../execution/synchronization/enable

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Enable synchronization. Trigger generation will only start once all workers have reported a ready status. Synchronization checks will be repeated with the same trigger generation settings (holdoff and repetitions) until synchronization is disabled.

FEATURES

/dev..../features/code

Properties: Write
Type: String
Unit: None

Node providing a mechanism to write feature codes.

/dev..../features/devtype

Properties: Read
Type: String
Unit: None

Returns the device type.

/dev..../features/options

Properties: Read
Type: String
Unit: None

Returns enabled options.

/dev..../features/serial

Properties: Read
Type: String
Unit: None

Device serial number.

FEEDBACK

/dev..../feedback/decoder/lut/sources/n/index

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The index of the bit in the readout register used as source address of the Lookup Table.

/dev..../feedback/decoder/lut/sources/n/register

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The readout register used as source address of the Lookup Table.

/dev..../feedback/decoder/lut/tables/n

Properties: Read, Write
Type: ZIVectorData
Unit: None

The lookup Table. A vector of 2^16 elements, each represents the output when its corresponding index is the source input address. Each element is an unsigned integer of 8 bits

/dev..../feedback/registerbank/reset

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Clear all the readout registers.

STATS

/dev..../stats/physical/fpga/aux

Properties: Read
Type: Double
Unit: V

Supply voltage of the FPGA.

/dev..../stats/physical/fpga/core

Properties: Read
Type: Double
Unit: V

Core voltage of the FPGA.

/dev..../stats/physical/fpga/temp

Properties: Read
Type: Double
Unit: °C

Internal temperature of the FPGA.

/dev..../stats/physical/overtemperature

Properties: Read
Type: Integer (64 bit)
Unit: None

This flag is set to 1 if the temperature of the FPGA exceeds 85°C. It will be reset to 0 after a restart of the device.

STATUS

/dev..../status/flags/binary

Properties: Read
Type: Integer (64 bit)
Unit: None

A set of binary flags giving an indication of the state of various parts of the device. Reserved for future use.

/dev..../status/time

Properties: Read
Type: Integer (64 bit)
Unit: None

The current timestamp.

SYSTEM

/dev..../system/activeinterface

Properties: Read
Type: String
Unit: None

Currently active interface of the device.

/dev..../system/boardrevisions/n

Properties: Read
Type: String
Unit: None

Hardware revision of the FPGA base board

/dev..../system/clocks/ready

Properties: Read
Type: Integer (64 bit)
Unit: None

Advises to wait 30 minutes after boot before locking to external reference clock.

/dev..../system/clocks/referenceclock/in/freq

Properties: Read
Type: Double
Unit: Hz

Indicates the frequency of the reference clock.

/dev..../system/clocks/referenceclock/in/source

Properties: Read, Write, Setting
Type: Integer (enumerated)
Unit: None

The intended reference clock source. When the source is changed, all the instruments connected with ZSync links will be disconnected. The connection should be re-established manually.

0 "internal": The internal clock is intended to be used as the frequency and time base reference.
1 "external": An external clock is intended to be used as the frequency and time base reference. Provide a clean and stable 10 MHz or 100 MHz reference to the appropriate back panel connector.
/dev..../system/clocks/referenceclock/in/sourceactual

Properties: Read
Type: Integer (enumerated)
Unit: None

The actual reference clock source.

0 "internal": The internal clock is used as the frequency and time base reference.
1 "external": An external clock is used as the frequency and time base reference.
/dev..../system/clocks/referenceclock/in/status

Properties: Read
Type: Integer (enumerated)
Unit: None

Status of the reference clock.

0 "locked": Reference clock has been locked on.
1 "error": There was an error locking onto the reference clock signal.
2 "busy": The device is busy trying to lock onto the reference clock signal.
/dev..../system/clocks/referenceclock/out/enable

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Enable clock signal on the reference clock output. When the clock output is turned on or off, all the instruments connected with ZSync links will be disconnected. The connection should be re-established manually.

/dev..../system/clocks/referenceclock/out/freq

Properties: Read, Write, Setting
Type: Double
Unit: Hz

Select the frequency of the output reference clock. Only 10 MHz and 100 MHz are allowed. When the frequency is changed, all the instruments connected with ZSync links will be disconnected. The connection should be re-established manually.

/dev..../system/fpgarevision

Properties: Read
Type: Integer (64 bit)
Unit: None

HDL firmware revision.

/dev..../system/fwlog

Properties: Read
Type: String
Unit: None

Returns log output of the firmware.

/dev..../system/fwlogenable

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Enables logging to the fwlog node.

/dev..../system/fwrevision

Properties: Read
Type: Integer (64 bit)
Unit: None

Revision of the device-internal controller software.

/dev..../system/fx3revision

Properties: Read
Type: String
Unit: None

USB firmware revision.

/dev..../system/identify

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Setting this node to 1 will cause the device to blink the power led for a few seconds.

/dev..../system/kerneltype

Properties: Read
Type: String
Unit: None

Returns the type of the data server kernel (mdk or hpk).

/dev..../system/nics/n/defaultgateway

Properties: Read, Write
Type: String
Unit: None

Default gateway configuration for the network connection.

/dev..../system/nics/n/defaultip4

Properties: Read, Write
Type: String
Unit: None

IPv4 address of the device to use if static IP is enabled.

/dev..../system/nics/n/defaultmask

Properties: Read, Write
Type: String
Unit: None

IPv4 mask in case of static IP.

/dev..../system/nics/n/gateway

Properties: Read
Type: String
Unit: None

Current network gateway.

/dev..../system/nics/n/ip4

Properties: Read
Type: String
Unit: None

Current IPv4 of the device.

/dev..../system/nics/n/mac

Properties: Read
Type: String
Unit: None

Current MAC address of the device network interface.

/dev..../system/nics/n/mask

Properties: Read
Type: String
Unit: None

Current network mask.

/dev..../system/nics/n/saveip

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

If written, this action will program the defined static IP address to the device.

/dev..../system/nics/n/static

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Enable this flag if the device is used in a network with fixed IP assignment without a DHCP server.

/dev..../system/porttcp

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Returns the current TCP port used for communication to the dataserver.

/dev..../system/portudp

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Returns the current UDP port used for communication to the dataserver.

/dev..../system/powerconfigdate

Properties: Read
Type: Integer (64 bit)
Unit: None

Contains the date of power configuration (format is: (year << 16) | (month << 8) | day)

/dev..../system/preset/busy

Properties: Read
Type: Integer (64 bit)
Unit: None

Indicates if presets are currently loaded.

/dev..../system/preset/error

Properties: Read
Type: Integer (64 bit)
Unit: None

Indicates if the last operation was illegal. Successful: 0, Error: 1.

/dev..../system/preset/load

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Load the selected preset.

/dev..../system/properties/timebase

Properties: Read
Type: Double
Unit: s

Minimal time difference between two timestamps. The value is equal to 1/(maximum sampling rate).

/dev..../system/saveports

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Flag indicating that the TCP and UDP ports should be saved.

/dev..../system/shutdown

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Sending a '1' to this node initiates a shutdown of the operating system on the device. It is recommended to trigger this shutdown before switching the device off with the hardware switch at the back side of the device.

/dev..../system/stall

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Indicates if the network connection is stalled.

/dev..../system/update

Properties: Read, Write
Type: Integer (64 bit)
Unit: None

Requests update of the device firmware and bitstream from the dataserver.

TRIGGERS

/dev..../triggers/out/n/enable

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Enable the Trigger Out.

/dev..../triggers/out/n/port

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The ZSync port associated with the Trigger Out source.

/dev..../triggers/out/n/pulsewidth

Properties: Read
Type: Double
Unit: s

Defines the minimum pulse width of the generated pulses.

/dev..../triggers/out/n/source

Properties: Read, Write, Setting
Type: Integer (enumerated)
Unit: None

Select the source of the trigger Out.

0 "start_trigger": Generate a trigger when a "start trigger" is sent over the selected ZSync.
1 "feedback": Generate a trigger when feedback is sent over the selected ZSync.

ZSYNCS

/dev..../zsyncs/n/connection/alias

Properties: Read, Write, Setting
Type: ZIVectorData
Unit: None

User-given name to the instrument connected to this port.

/dev..../zsyncs/n/connection/devtype

Properties: Read
Type: ZIVectorData
Unit: None

The device type of the instrument connected to this port.

/dev..../zsyncs/n/connection/serial

Properties: Read
Type: ZIVectorData
Unit: None

The device ID of the instrument connected to this port.

/dev..../zsyncs/n/connection/status

Properties: Read
Type: Integer (enumerated)
Unit: None

The current status of the instrument connected to the port.

0 No connection
1 Connection in progress
2 Connected
3 Connection error
/dev..../zsyncs/n/output/decoder/source

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The index of the lookup table in the LUT decoder that is forwarded.

/dev..../zsyncs/n/output/enable

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Enable feedback for a given port.

/dev..../zsyncs/n/output/registerbank/sources/n/enable

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

Enable readout register forwarding of bits 2m, 2m+1 to the port n.

/dev..../zsyncs/n/output/registerbank/sources/n/index

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The index of the results in the readout register to be forwarded.

/dev..../zsyncs/n/output/registerbank/sources/n/register

Properties: Read, Write, Setting
Type: Integer (64 bit)
Unit: None

The readout register to be forwarded.

/dev..../zsyncs/n/output/source

Properties: Read, Write, Setting
Type: Integer (enumerated)
Unit: None

Select the feedback source for a given port.

0 "reg", "register_forwarding": Register Forwarding
1 "dec", "decoder": Decoder