PrimaryEmulatedQuadratureDivider Parameter
Default Value: 1.0
Minimum Value: 1.0
Maximum Value: 65536.0
Units: None
Type: float
HARDWARE: This parameter applies only to the drives and configurations that follow:
Table: Applicable Drive Types and Feedback Options
Drive Type | Feedback Option |
---|---|
FLEX | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
GL4 | Using an encoder multiplier |
iXC2e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XC2e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
iXC4e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XC4e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
iXC6e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XC6e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
iXL2e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XL2e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XL4s | Using an encoder multiplier |
iXL5e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
XL5e | Using an encoder multiplier with the -MX2 or -MX3 multiplier option |
iXR3 | Using an encoder multiplier with the -CT2 or -CT4 multiplier option |
XR3 | Using an encoder multiplier with the -CT2 or -CT4 multiplier option |
IMPORTANT: If the Primary Feedback connector is configured as PSO Distance input or PSO Window input, your drive adds a fixed latency of 800 nanoseconds when you use the encoder multiplier.
When the value of the PrimaryEmulatedQuadratureDivider parameter increases, the quadrature multiplication factor of the emulated quadrature signals that the drive generates from the primary encoder multiplier feedback module decreases.
The default value of the PrimaryEmulatedQuadratureDivider is 1. Change this parameter from the default value only when the system resolution and speed of motion cause the maximum encoder frequency of the axis to be greater than the maximum quadrature output frequency of the drive. The maximum quadrature output frequency of all Automation1 drives is 100 MHz (counts per second). You can use the Drive Encoder Output feature to send the emulated quadrature signals from the drive. The maximum frequency of the Drive Encoder Output is 25 MHz. To calculate the maximum encoder frequency of the axis based on the features you want to use, use the equation that follows:
If you are using the Drive Encoder Output feature to send the emulated quadrature signals from the drive:
- If the maximum encoder frequency is less than or equal to 25 MHz, use the default value of 1.
- If the maximum encoder frequency is greater than 25 MHz, change the parameter from the default value.
If you are not using the Drive Encoder Output feature to send the emulated quadrature signals from the drive:
- If the maximum encoder frequency is less than or equal to 100 MHz, use the default value of 1.
- If the maximum encoder frequency is greater than 100 MHz, change the parameter from the default value.
Changing the PrimaryEmulatedQuadratureDivider from the default value:
The non-default value does not change the resolution of the servo loop.
The quadrature multiplication factor is equal to the value of the PrimaryEncoderMultiplicationFactor parameter divided by the value of the PrimaryEmulatedQuadratureDivider parameter. See the equation that follows.
The quadrature multiplication factor must obey the conditions that follow:
- It must be an integer to get a whole number of quadrature pulses per encoder cycle. If it is not an integer, the controller rounds the result to the nearest integer and a small difference occurs between the expected quadrature resolution and the actual quadrature resolution.
- The value of the integer must be greater than 4. If it is not greater than 4, the drive will not generate emulated quadrature signals.
- The value of the integer must be greater than the minimum frequency divider. Use this equation to calculate the minimum frequency divider.
IMPORTANT: When the value of the PrimaryEmulatedQuadratureDivider parameter increases, the quadrature multiplication factor of the quadrature signals that are used for PSO tracking decreases. If you set this parameter to a non-default value, divide your PSO firing distances by the value that you set for this parameter. For example, if you set the PrimaryEmulatedQuadratureDivider to a value of 2, you must divide all PSO firing distances by a factor of 2.
When you use the encoder multiplier, the drive may generate emulated quadrature signals that are not exactly the same as the encoder position. When the drive samples a sine wave encoder and generates emulated quadrature signals, it can only give an integer number of counts per encoder sample, up to the maximum quadrature encoder output frequency (100 MHz). This can cause jitter between counts of generated emulated quadrature signals. The table that follows specifies the jitter at different encoder input frequencies.
Table: Jitter Specifications
Input Frequency (counts/second) | Jitter |
---|---|
< 10 MHz | +/- 100 nanoseconds |
10 to 20 MHz | +/- 25 nanoseconds |
20 to 30 MHz | +/- 8.33 nanoseconds |
30 to 40 MHz | +/- 4.17 nanoseconds |
40 to 50 MHz | +/- 2.5 nanoseconds |
50 to 60 MHz | +/- 1.67 nanoseconds |
60 to 70 MHz | +/- 1.19 nanoseconds |
70 to 80 MHz | +/- 0.89 nanoseconds |
80 to 90 MHz | +/- 0.69 nanoseconds |
90 to 100 MHz | +/- 0.55 nanoseconds |