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v10.0.1.x for R2026a
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IO421 - LVDT/RVDT Read

IO421 - LVDT/RVDT Read — Reads the IO421 LVDT/RVDT inputs

Library

Simulink Real-Time - Speedgoat

Description

The IO421-1 sub-module measures up to four Linear or Rotary Variable Differential Transformers. Each channel has separate inputs for the reference (excitation) and the A/B signals.

The characteristics of the sub-module depend on the factory configuration selected at the time of the order. This information is available in a separate documentation shipped with the device.

sub-module codeInput (VLL)[VRMS ]Ref (VREF)[VRMS ]Frequency [Hz]
LB2 - 282 - 28400 - 1k
LC2 - 282 - 281k - 3k
LD2 - 282 - 283k - 5k
LE2 - 282 - 285k - 7k
LF2 - 282 - 287k - 10k
LG2 - 282 - 2810k - 20k
LXxxx

See section IO421-1 LVDT/RVDT connection methods in the 'Usage notes' section for more information about the various connection methods.

Ports

Outputs
Position n (n is the channel number)

The measured position of the ferromagnetic rod during runtime. The output range is between -1 and +1. The number of these ports is dependent on the channel count, which is specified by the 'Active Channels' parameter.

Parameters

Module ID

A unique module ID must be used for each type of IO421 module block in your model.

The module ID has two functions:

  • It defines the logical connection to link the I/O module driver blocks with each other

  • It also has an impact on the PCI slot auto-search feature: if only one I/O module is installed, the module ID must be set to 1. If multiple modules are installed, it must be in the range 1:n. Not all the I/O modules installed in the target machine need to be used

Slot

The carrier board can contain up to three modules. This parameter indicates where your IO421-1 is located.

Active Channels

Select the active input/output channels in a vector. A defined number of channels can be selected using square brackets, for example [1 2 3]. A sequence of channels can be selected using a colon, for example, 1:4.

Wiring Mode

The wiring method used for the connected LVDT/RVDT device. A value of '0' selects 2-wire mode, '1' selects 3- or 4-wire mode. You can either use a scalar value, which applies to all channels, or a vector which is mapped to the Channels vector. See section 'IO421-1 LVDT/RVDT connection methods' in the 'Usage notes' of this document for information about the various connection methods.

Expected Signal Voltage VLL

Enter the expected voltage of the A/B signals in (V RMS). You can either use a scalar value, which applies to all channels, or a vector which is mapped to the Channels vector.

Expected Signal Voltage VREF

Enter the expected voltage of the R signal (reference/excitation) in (V RMS). You can either use a scalar value, which applies to all channels, or a vector which is mapped to the Channels vector.

Sample Time

Defines the base sample time at which this driver block gets its sample hit. This parameter can also be set to -1 for inherited sample time. The units are in seconds.

PCI Slot (-1: auto-search)

There are two approaches for mapping this block to a specific I/O module installed in your target machine. All modules of the same type must be configured using the same method.

  • Auto-Search: with the default value -1 the I/O module will be automatically located in the target machine. If you have multiple modules of the same kind, the Module ID defines which module is associated with this block. To see how each I/O module maps to a Module ID, use this Speedgoat API:

    speedgoat.getIoInterfaces("TargetName", "mySpeedgoat")

  • Explicit Addressing: to explicitly define the logical address of the I/O module in the target machine, you can provide the PCI bus and slot numbers as a vector: [bus, slot]. To determine these numbers, run the following command in the MATLAB command window:

    speedgoat.getIoInterfaces("TargetName", "mySpeedgoat", "Advanced", true)

    Note that the PCI address can change whenever an I/O module is added or removed – usually, auto-search is the best option.