Win32_1394ControllerDevice

The Win32_1394ControllerDevice association WMI class relates the high-speed serial bus (IEEE 1394 Firewire) Controller and the CIM_LogicalDevice instance connected to it. This serial bus provides e...

The Win32_1394ControllerDevice association WMI class relates the high-speed serial bus (IEEE 1394 Firewire) Controller and the CIM_LogicalDevice instance connected to it. This serial bus provides enhanced connectivity for a wide range of devices, including consumer audio or video components, storage peripherals, other computers, and portable devices. IEEE 1394 has been adopted by the consumer electronics industry and provides a Plug and Play-compatible expansion interface.

Methods

Win32_1394ControllerDevice has no methods.

Properties

Win32_1394ControllerDevice returns 7 properties:

'AccessState','Antecedent','Dependent','NegotiatedDataWidth','NegotiatedSpeed',
'NumberOfHardResets','NumberOfSoftResets'

Unless explicitly marked as writeable, all properties are read-only. Read all properties for all instances:

Get-CimInstance -ClassName Win32_1394ControllerDevice -Property *

Most WMI classes return one or more instances.

When Get-CimInstance returns no result, then apparently no instances of class Win32_1394ControllerDevice exist. This is normal behavior.

Either the class is not implemented on your system (may be deprecated or due to missing drivers, i.e. CIM_VideoControllerResolution), or there are simply no physical representations of this class currently available (i.e. Win32_TapeDrive).

AccessState

UINT16

Indicates whether the controller is actively commanding or accessing the device. This information is necessary when a logical device can be commanded by, or accessed through, multiple controllers.

AccessState returns a numeric value. To translate it into a meaningful text, use any of the following approaches:

Use a PowerShell Hashtable
$AccessState_map = @{
      0 = 'Unknown'
      1 = 'Active'
      2 = 'Inactive'
}
Use a switch statement
switch([int]$value)
{
  0          {'Unknown'}
  1          {'Active'}
  2          {'Inactive'}
  default    {"$value"}
}
Use Enum structure
Enum EnumAccessState
{
  Unknown    = 0
  Active     = 1
  Inactive   = 2
}

Examples

Use $AccessState_map in a calculated property for Select-Object
<# 
  this example uses a hashtable to translate raw numeric values for 
  property "AccessState" to friendly text

  Note: to use other properties than "AccessState", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "AccessState" 
# to translate other properties, use their translation table instead
$AccessState_map = @{
      0 = 'Unknown'
      1 = 'Active'
      2 = 'Inactive'
}

#endregion define hashtable

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "AccessState", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$AccessState = @{
  Name = 'AccessState'
  Expression = {
    # property is an array, so process all values
    $value = $_.AccessState
    $AccessState_map[[int]$value]
  }  
}
#endregion define calculated property

# retrieve the instances, and output the properties "Caption" and "AccessState". The latter
# is defined by the hashtable in $AccessState: 
Get-CimInstance -Class Win32_1394ControllerDevice | Select-Object -Property Caption, $AccessState

# ...or dump content of property AccessState:
$friendlyValues = Get-CimInstance -Class Win32_1394ControllerDevice | 
    Select-Object -Property $AccessState |
    Select-Object -ExpandProperty AccessState

# output values
$friendlyValues

# output values as comma separated list
$friendlyValues -join ', '

# output values as bullet list
$friendlyValues | ForEach-Object { "- $_" }
Use $AccessState_map to directly translate raw values from an instance
<# 
  this example uses a hashtable to manually translate raw numeric values 
  for property "Win32_1394ControllerDevice" to friendly text. This approach is ideal when
  there is just one instance to work with.

  Note: to use other properties than "Win32_1394ControllerDevice", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "Win32_1394ControllerDevice" 
# to translate other properties, use their translation table instead
$AccessState_map = @{
      0 = 'Unknown'
      1 = 'Active'
      2 = 'Inactive'
}

#endregion define hashtable

# get one instance:
$instance = Get-CimInstance -Class Win32_1394ControllerDevice | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to illustrate
  the number-to-text translation. To process all instances, replace
  "Select-Object -First 1" with a "Foreach-Object" loop, and use
  the iterator variable $_ instead of $instance
#>

# query the property
$rawValue = $instance.AccessState  

# translate raw value to friendly text:
$friendlyName = $AccessState_map[[int]$rawValue]

# output value
$friendlyName
Use a switch statement inside a calculated property for Select-Object
<# 
  this example uses a switch clause to translate raw numeric 
  values for property "AccessState" to friendly text. The switch
  clause is embedded into a calculated property so there is
  no need to refer to external variables for translation.

  Note: to use other properties than "AccessState", look up the appropriate 
  translation switch clause for the property you would like to use instead.
#>

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "AccessState", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$AccessState = @{
  Name = 'AccessState'
  Expression = {
    # property is an array, so process all values
    $value = $_.AccessState
    
    switch([int]$value)
      {
        0          {'Unknown'}
        1          {'Active'}
        2          {'Inactive'}
        default    {"$value"}
      }
      
  }  
}
#endregion define calculated property

# retrieve all instances...
Get-CimInstance -ClassName Win32_1394ControllerDevice | 
  # ...and output properties "Caption" and "AccessState". The latter is defined
  # by the hashtable in $AccessState:
  Select-Object -Property Caption, $AccessState
Use the Enum from above to auto-translate the code values
<# 
  this example translates raw values by means of type conversion
  the friendly names are defined as enumeration using the
  keyword "enum" (PowerShell 5 or better)
  
  The raw value(s) are translated to friendly text by 
  simply converting them into the enum type.
  
  Note: to use other properties than "Win32_1394ControllerDevice", look up the appropriate 
  enum definition for the property you would like to use instead.
#>


#region define enum with value-to-text translation:
Enum EnumAccessState
{
  Unknown    = 0
  Active     = 1
  Inactive   = 2
}

#endregion define enum

# get one instance:
$instance = Get-CimInstance -Class Win32_1394ControllerDevice | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to focus on
  the number-to-text type conversion. 
  
  To process all instances, replace   "Select-Object -First 1" 
  with a "Foreach-Object" loop, and use the iterator variable 
  $_ instead of $instance
#>

# query the property:
$rawValue = $instance.AccessState

#region using strict type conversion

<#
  Note: strict type conversion fails if the raw value is 
  not defined by the enum. So if the list of allowable values
  was extended and the enum does not match the value,
  an exception is thrown
#>

# convert the property to the enum **AccessState** 
[EnumAccessState]$rawValue 

# get a comma-separated string:
[EnumAccessState]$rawValue -join ',' 
#endregion

#region using operator "-as"

<#
  Note: the operator "-as" accepts values not defined
  by the enum and returns $null instead of throwing
  an exception
#>

$rawValue -as [EnumAccessState]
#endregion

Enums must cover all possible values. If AccessState returns a value that is not defined in the enum, an exception occurs. The exception reports the value that was missing in the enum. To fix, add the missing value to the enum.

Antecedent

KEY PROPERTY WIN32_1394CONTROLLER

The Win32_1394Controller antecedent reference represents the 1394 controller associated with this device.

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent

Dependent

KEY PROPERTY CIM_LOGICALDEVICE

The CIM_LogicalDevice dependent reference represents the CIM_LogicalDevice connected to the 1394 controller.

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent

NegotiatedDataWidth

UINT32 “BITS”

When several bus or connection-data widths are possible, this property defines the one in use between the devices. Data width is specified in bits. If data width is not negotiated, or if this information is not available or important to device management, the property should be set to 0 (zero).

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent, NegotiatedDataWidth

NegotiatedSpeed

UINT64 “BITS PER SECOND”

When several bus or connection speeds are possible, this property defines the one being used between the devices. Speed is specified in bits-per-second. If connection or bus speeds are not negotiated, or if this information is not available or important to device management, the property should be set to 0 (zero).

For more information about using uint64 values in scripts, see Scripting in WMI.

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent, NegotiatedSpeed

NumberOfHardResets

UINT32

Number of hard resets issued by the controller. A hard reset returns the device to its initialization or boot-up state. All internal device state information and data are lost.

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent, NumberOfHardResets

NumberOfSoftResets

UINT32

Number of soft resets issued by the controller. A soft reset does not completely clear current device state and data. Exact semantics are dependent on the device and on the protocols and mechanisms used to communicate to it.

Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property Antecedent, Dependent, NumberOfSoftResets

Examples

List all instances of Win32_1394ControllerDevice
Get-CimInstance -ClassName Win32_1394ControllerDevice

Learn more about Get-CimInstance and the deprecated Get-WmiObject.

View all properties
Get-CimInstance -ClassName Win32_1394ControllerDevice -Property *
View key properties only
Get-CimInstance -ClassName Win32_1394ControllerDevice -KeyOnly

Selecting Properties

To select only some properties, pipe the results to Select-Object -Property a,b,c with a comma-separated list of the properties you require. Wildcards are permitted.

Get-CimInstance always returns all properties but only retrieves the ones that you specify. All other properties are empty but still present. That’s why you need to pipe the results into Select-Object if you want to limit the visible properties, i.e. for reporting.

Selecting Properties

The code below lists all available properties. Remove the ones you do not need:

$properties = 'AccessState',
              'Antecedent',
              'Dependent',
              'NegotiatedDataWidth',
              'NegotiatedSpeed',
              'NumberOfHardResets',
              'NumberOfSoftResets'
Get-CimInstance -ClassName Win32_1394ControllerDevice | Select-Object -Property $properties
Limiting Network Bandwidth

If you work remotely, it makes sense to limit network bandwidth by filtering the properties on the server side, too:

Get-CimInstance -Class Win32_1394ControllerDevice -Property $property | 
Select-Object -Property $property

Selecting Instances

To select some instances, use Get-CimInstance and a WMI Query. The wildcard character in WMI Queries is % (and not “*”).

The parameter -Filter runs a simple query.

Listing all instances where the property Caption starts with “A”
Get-CimInstance -Class Win32_1394ControllerDevice -Filter 'Caption LIKE "a%"' 
Using a WQL Query

The parameter -Query uses a query similar to SQL and combines the parameters -Filter and -Property. This returns all instances where the property Caption starts with “A”, and returns the properties specified:

Get-CimInstance -Query "SELECT NumberOfHardResets, Dependent, NegotiatedSpeed, Antecedent FROM Win32_1394ControllerDevice WHERE Caption LIKE 'a%'"

Any property you did not specify is still present but empty. You might need to use Select-Object to remove all unwanted properties:

Get-CimInstance -Query "SELECT NumberOfHardResets, Dependent, NegotiatedSpeed, Antecedent FROM Win32_1394ControllerDevice WHERE Caption LIKE 'a%'" | Select-Object -Property NumberOfHardResets, Dependent, NegotiatedSpeed, Antecedent

Accessing Remote Computers

To access remote systems, you need to have proper permissions. User the parameter -ComputerName to access one or more remote systems.

Authenticating as Current User
# one or more computer names or IP addresses:
$list = 'server1', 'server2'

# authenticate with your current identity:
$result = Get-CimInstance -ClassName Win32_1394ControllerDevice -ComputerName $list 
$result
Authenticating as Different User

Use a CIMSession object to authenticate with a new identity:

# one or more computer names or IP addresses:
$list = 'server1', 'server2'

# authenticate with a different identity:
$cred = Get-Credential -Message 'Authenticate to retrieve WMI information:'
$session = New-CimSession -ComputerName $list -Credential $cred

$result = Get-CimInstance Win32_1394ControllerDevice -CimSession $session

# remove the session after use (if you do not plan to re-use it later)
Remove-CimSession -CimSession $session

$result

Learn more about accessing remote computers.

Requirements

To use Win32_1394ControllerDevice, the following requirements apply:

PowerShell

Get-CimInstance was introduced with PowerShell Version 3.0, which in turn was introduced on clients with Windows 8 and on servers with Windows Server 2012.

If necessary, update Windows PowerShell to Windows PowerShell 5.1, or install PowerShell 7 side-by-side.

Operating System

Win32_1394ControllerDevice was introduced on clients with Windows Vista and on servers with Windows Server 2008.

Namespace

Win32_1394ControllerDevice lives in the Namespace Root/CIMV2. This is the default namespace. There is no need to use the -Namespace parameter in Get-CimInstance.

Implementation

Win32_1394ControllerDevice is implemented in CIMWin32.dll and defined in CIMWin32.mof. Both files are located in the folder C:\Windows\system32\wbem:

explorer $env:windir\system32\wbem
notepad $env:windir\system32\wbem\CIMWin32.mof