We’re back with our second post in a series of resources on CUI’s range of rotary encoders. Last week, we discussed the design challenges that need to be considered when implementing motion control feedback loops. This week, we look at the perks of digital encoders.
It is no surprise that encoder users have been nervous about employing new technologies on the ‘shop floor’. Despite the very simple job they have, to indicate the position of the motor shaft to the system controller, it is crucial in automation, with that information determining speed, direction, acceleration and windings.
Traditionally, as discussed last week, both optical and magnetic technologies have been the mainstay when designing motion control feedback loops. Capacitive encoding is the ‘third way’, offering all the benefits of optical and magnetic designs without their weaknesses. The beauty of the technology, using the same principle as the well-established digital vernier caliper, is that there is nothing to wear out and because of its design it is immune to contaminants such as dust, dirt and oil, frequently found in the environments encoders are deployed in.
There are also advantages to be found in the digital nature of the device. Including the ability to adjust the resolution, without the need to change to a higher, or lower resolution encoder. The digital output of the device brings design into the 21st century, open up many new opportunities in design, installation and maintenance. This is because traditional magnetic or optical encoders are functional yet ‘dumb’ and offer no flexibility. Because the capacitive encoder is digitally based, using a built-in ASIC and microcontroller, it is able to offer numerous additional features and enhanced performance and flexibility. This technology, however, still remains entirely compatible with standard output encoders.
Looking a little more at the CUI AMT31 series as an example. There are significant benefits of digital that are welcome news for design engineers looking for innovation, reliability and ease of use in motion control feedback loops:
- It enables simple ‘one touch’ zeroing. A straightforward process, the shaft is locked into the desired position by energising the proper motor phases, and command the encoder to ‘zero at this position.
- A single capacitive encoder can support a wide range of resolution and pole-pair values. Designers can use this programmable resolution capability to dynamically adjust response and performance of PID control loops during development, without the need to purchase and install new encoders.
- Having a digital interface simplifies the bill of materials. There is no longer a need to list and stock various versions often required in a multi-motor product.
- Using the Windows PC based AMt Viewpoint™ software for CUI capacitive encoders speeds development, turning time-consuming mundane tasks into simple operations.
For more information, check out the link below for more videos and demos of CUI capacitive encoders.