This release of the Win32 version of the Vaunix Lab Brick Attenuator DLL contains a test program which can
be built using Visual Studio 2019. Only the x64 configuration of the test program is supported by this SDK.

The VNX_atten64(USB)DLL supports:
LDA-102
LDA-602
LDA-302P-H
LDA-302P-1
LDA-302P-2
LDA-102E
LDA-602E
LDA-102-75
LDA-203
DA-602EH
LDA-602Q
LDA-906V
LDA-133
LDA-5018
LDA-5040
LDA-906V-8
LDA-802EH
LDA-802Q
LDA-802-8
LDA-8X1-752
LDA-908V
LDA-908V-4
LDA-908V-8
LDA-403

The VNX_Eth_Attn64(Ethernet) DLL supports:
LDA-602Q
LDA-802EH
LDA-802Q

The DLL has ANSI-C style naming, but uses the standard x64 calling sequence. The ANSI-C style naming was chosen to simplify the task of accessing
the DLL functions from other languages such as Python or Tcl. A 32bit version with a VB6 compatible calling convention is available upon request.

The DLL relies on run time libraries from the current versions of Windows, and therefore may require installation of the Visual Studio 2019 
redistributable libraries on some systems.

USB -- DLL 
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Note that although all attenuation values are specified in the units of .25db, or optionally .1db using the HR functions, the minimum attenuation
increment is determined by the Lab Brick hardware. The LDA-102, LDA-102E, LDA-602, LDA-602E, LDA-102-75 and LDA-302P-H attenuators have a minimum
attenuation increment of .5db. The LDA-302P-1 has a minimum attenuation increment of 1db, and the LDA-302P-2 has a minimum attenuation increment
of 2db. The Lab Brick Attenuator DLL will round down any attenuation value that has a higher resolution than the hardware supports. Thus, for example,
calling the fnLDA_SetAttenuation function with an attenuation value of 42 will result in 10.5db of attenuation on an LDA-102, and 10db of attenuation
on an LDA-302P-1.

For the high resolution attenuators, such as the LDA-602EH, LDA-602Q, and LDA-906V you should use the high resolution functions with names ending in "HR"
to take advantage of the full resolution of the devices. 

The LDA-602Q and LDA-802Q have four channels. To select a channel, use the fnLDA_SetChannel(DEVID deviceID, int channel) function. Channels are numbered from 1 to 4.
The LDA-906V-8 has eight channels, numbered from 1 to 8, as does the LDA-802-8.  Expandable LDA devices such as the LDA-8X1-752 may have up to 64 channels.
Use the fnLDA_GetNumChannels(DEVID deviceID) function to determine how many channels are available.

The function fnLDA_SetAttenuationHRQ(DEVID deviceID, int attenuation, int channel) combines the SetChannel and SetAttenuation functions to simplify test
software that uses the LDA-602Q quad attenuator or the LDA-906V-8 attenuator. After calling the function the channel will be set to the new channel value.

The function fnLDA_StartRampMC allows an application program to start ramps on multiple channels simultaneously. The function fnLDA_StartProfileMC provides similar functionality
for starting attenuation profiles on multiple channels simultaneously. The fnLDA_StartRampMC function is not supported for expandable LDA devices such as the LDA-8X1-752.

Several new functions have been added to support the long profiles available on some LDA models, and multiple channel ramps and profiles. See the .h file and
example programs.

Support for expandable LDA devices has been enhanced.

Ethernet -- DLL
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Released 7/16/2021