This page includes the following components: Resolver  Name  Specifies the name of the resolver.  Description  Specifies a description for the resolver.  Angle Conditioning 

 Symbol  Units  Default  Description 

Number of Pole Pairs  pp 
 1  A gain applied to the mechanical angle of the machine, θ_{m}, before it is translated to an electrical resolver signal. Modify this parameter if the resolver is attached to a gear box rather than connected directly to the rotor. To generate resolver signals whose speed corresponds to the mechanical speed of the machine, set this value to 1. See the Resolver Model Equations for more information.  Angle Offset  θ_{Offset}  Degrees  0°  Offset from the mechanical angle of the machine θ_{m}.  Reverse Speed 

 Disabled  Reverses the direction of the resolver when enabled.  Gain Configuration 
 Symbol  Units  Default  Description 

Sine.Sine Gain  Sin.Sin 
 0.999985  Sine gain applied to the Sine output signal. See the Resolver Model Equations for more information.  Sine.Cos Gain  Sin.Cos 
 0  Cosine gain applied to the Sine output signal. See the Resolver Model Equations for more information.  Cos.Sin Gain  Cos.Sin 
 0  Sine gain applied to the Cosine output signal. See the Resolver Model Equations for more information.  Cos.Cos Gain  Cos.Cos 
 0.999985  Cosine gain applied to the Cosine Output signals. See the Resolver Model Equations for more information.  Excitation Conditioning 
 Symbol  Units  Default  Description 

Sampling Frequency  T_{s}  MHz  1MHz  The frequency at which the Excitation Carrier signal is sampled to determine the Sine and Cosine outputs. See Resolver Excitation Signal for more information.  Phase Delay  T_{pd}  microseconds  0us  Creates a phase delay in the output Sine and Cosine signals. This is used to simulate a physical delay in nonideal resolvers. 
Resolver Model DescriptionA resolver is a sensor that provides feedback about the angular position and velocity of a rotating component, such as the rotor of an electrical motor.
Figure 1. An example of a operating resolver where a sinusoidal excitation signal is input into the resolver and the result is two output signals, Sine Output and Cosine Output During operation, a sinusoidal excitation signal is provided to the resolver. The resolver modulates the input excitation signal to produce two outputs representing sin(x) and cos(x), where x is the angle of the rotor. From the sin(x) and cos(x) signals controllers are reconstituted to calculate angular position of the machine.
Figure 2. Sine and Cosine signals generated by a resolver with an input Excitation sinusoidal signal.
Resolver Model EquationsThe resolver model outputs are calculated using the following sets of equations:
LaTeX Math Block 

anchor  SineOutput 

alignment  center 

 Sine \; Output = [Sin.Sin*sin(pp(\theta_m  \theta_{Offset})) + Sin.Cos * cos(pp * \theta_m  \theta_{Offset}))] * Excitation 
LaTeX Math Block 

anchor  CosineOutput 

alignment  center 

 Cosine \; Output = [Cos.Sin*sin(pp(\theta_m  \theta_{Offset})) + Cos.Cos * cos(pp * \theta_m  \theta_{Offset}))] * Excitation 
Where Sin.Sin, Sin.Cos, Cos.Sin, and Cos.Cos represent gains that are applied to simulate a nonideal resolver. To simulate an ideal resolver, set the Sin.Sin and Cos.Cos gains to 1, set the Sin.Cos and Cos.Sin gains to 0, set the pp to 1, and set the θ_{Offset} to 0. This results in the following equations:
LaTeX Math Block 

anchor  simpleSineOutput 

alignment  center 

 Sine \; Output = sin(\theta_m) * Excitation 
LaTeX Math Block 

anchor  simpleCosineOutput 

alignment  center 

 Cosine \; Output = cos(\theta_m) * Excitation 
Resolver Excitation SignalFor this resolver model, the excitation signal must be provided through an Analog Input channel. To confirm the index of the channel to use, refer to the pinout information for your hardware configuration in the Archived Hardware Configurations section. In most cases, the following channels are used: Motor 1  Analog Input 00  Motor 2 (if available)  Analog Input 01 
The amplitude of the excitation signal must be within a 1V to 1V range. If inputting a signal outside this range, use the Gain parameter for the Analog Input channel to manipulate the amplitude. Also note that the input signal must not exceed the specified voltage limitations of the hardware in any case. Typically, this hardware range is 10V to 10V, although the exact value can be confirmed on the description page of the Hardware Configuration. 