Difference between revisions of "Analog setpoint"
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* 10V equals most positive reference (+100%) | * 10V equals most positive reference (+100%) | ||
* Any value between is interpolated linearly | * Any value between is interpolated linearly | ||
| − | Another common voltage range is 0..5V where | + | Another common voltage range is 0..5V where zero reference may be at 2.5 VDC (bias voltage). |
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==Example== | ==Example== | ||
Lets assume +/-10V is used as torque reference in VSD drive. In this case 0V equals no torque, and 10V equals 100% of peak torque configured in the drive, 5V equals 50% torque etc. | Lets assume +/-10V is used as torque reference in VSD drive. In this case 0V equals no torque, and 10V equals 100% of peak torque configured in the drive, 5V equals 50% torque etc. | ||
Peak torque can be configured to drive with [[GDtool]] as peak current limit. Torque and current are directly proportional, so torque reference is also a current reference. | Peak torque can be configured to drive with [[GDtool]] as peak current limit. Torque and current are directly proportional, so torque reference is also a current reference. | ||
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==Differential signaling== | ==Differential signaling== | ||
Analog reference input in target device is typically differential. Differential input requires 3 wires from source device: | Analog reference input in target device is typically differential. Differential input requires 3 wires from source device: | ||
Revision as of 14:38, 26 March 2012
Analog reference is one of reference signal types used in motion control.
The most typical reference voltage range is +/-10V where
- -10V equals the most negative reference (-100%)
- 0V equals zero reference
- 10V equals most positive reference (+100%)
- Any value between is interpolated linearly
Another common voltage range is 0..5V where zero reference may be at 2.5 VDC (bias voltage).
Example
Lets assume +/-10V is used as torque reference in VSD drive. In this case 0V equals no torque, and 10V equals 100% of peak torque configured in the drive, 5V equals 50% torque etc.
Peak torque can be configured to drive with GDtool as peak current limit. Torque and current are directly proportional, so torque reference is also a current reference.
Differential signaling
Analog reference input in target device is typically differential. Differential input requires 3 wires from source device:
- Positive input
- Negative input
- Ground
The actual reference value will be calculated from the differential of positive and negative inputs. This eliminates error from ground currents and also reduces sensitivity to EMI noise.
