When choosing the PPR value of the encoder, please keep a few simple rules in mind. Make sure that you do not choose a PPR that will cause you to exceed the maximum frequency of your controller or encoder. Try to choose a PPR that is close to the value you wish to display, this eliminates or reduces the need for a calibration constant. For example, If you wish to display 12 inches for every revolution choose a PPR of 12. If you wish to display 12.00 inches, choose 1200 PPR. However, do not make the mistake of forgetting the multiplication of the controller's input. Most controllers have X2 or X4 logic. If it is X2 logic, this would change your PPR to 600 for a 12.00 display; and the PPR would be 300 for X4 logic. These choices give you one pulse for every one unit of measurement desired. It is important to remember the frequency that your PPR will create. When choosing the PPR, do not choose one that will result in a higher frequency than the encoder can handle at your max. speed. The reverse is also true, do not choose too low of a PPR, that your controller cannot recognize the signal. Try to choose your PPR so that your calibration constant is between .5 and 1.

How do I set my Calibration Constant?
The calibration constant can be simplified by simply selecting the correct Pulses Per Revolution (PPR). Once the PPR has been selected or is known simply follow the formula presented in the Technical Manual. When choosing your calibration constant remember the closer to 1 the better. The value of the calibration constant is your best resolution per pulse of the encoder.

Quadrature output refers to the phasing of the output signals. When the output signals, signal A and B, are 90 degrees out of phase with each other, the output is said to be in quadrature. This is the only thing that the term quadrature implies. (see What is a Quadrature output?)

x4 Logic denotes how the controller will interpret the signal that it is receiving. This is done by translating each edge of the pulse detected for the A and B channel into its own pulse. This translation takes place in the controller and not at the encoder.

This means if you order a quadrature encoder with 120 pulses per revolution, the output of signal A and B will be out of phase by 90 degrees. It does not mean that for every one revolution that the encoder makes you will get 480 pulses. The multiplication of the pulses only occurs at the controller

The A not and B not channels are the compliments of the A and B channels. This means that when signal A is high, signal A not is low and when A is low, signal A not is high. The same is true for any signal that has a compliment. This is commonly used to keep noise to a minimum. Some input cards will accept both the A and A not signal. It then compares the two signals to help eliminate common mode noise that may have been picked up on the line. This is done by accepting a pulse only when signal A is high and signal A not is low. This is true for any channel that has a compliment, signal A was used only as an example. This is commonly called a Differential Output.

Along with the industry proven features that the original Rim Tach 8500 is known for, the NexGen RT8 offers users advanced feedback technology. The NexGen RT8 boasts sensors that provide up to 0.075” of air gap, over 50% more than competitive models and an expanded resolution up to 2400 PPR. The RT8 circuitry was redesigned to offer on-board diagnostics with LED and alarm output. Also, an optimized pulse wheel offers greater shaft holding force and ease of assembly

We do not currently offer a return or buy back program for sensors and wheels of obsolete encoders. In this case, you would need to simply replace with old inventory with new sensors and wheels.

Unfortunately, sensors and wheels from older versions of the RT8 can not be used on the NexGen. The RT8 encoder is a direct replacement to the RIM Tach 8500; however, the sensors and wheels are not interchangeable between the two. The old and new can not read each other, therefore you can not mix and match old sensors to new wheels or vice versa. Replacing sensors and wheels for the NexGen is as simple as unbolting the old and bolting in the new.

The Rim Tach 8500 was obsoleted and replaced by the Next Gen Rim Tach 8500, also referred to as the RT8. For all intended puposes, the Next Gen RT8 is a direct replacement for the former RIM Tach 8500.

A resolver is a mainly mechanical device that provides an analog signal back to the encoder. Resolvers are ideal for applications where high temperature, high shock and vibration, and dust/ dirt are factors. Encoders differ from resolvers due to the fact that they are electrically powered devices devices and provide digital signal back to the encoder.

When selecting an encoder for applications in the food and beverage industry, an IP67 rated encoder is essential to withstand routine wash downs. Chemicals and other liquids involved in wash downs are very harsh on electrical devices. Stainless steel enclosures help ensure a sterile environment and continuously reliable feedback operation.

When you are experiencing an issue with an encoder, it is common to reach for the multi-meter. However, an oscilloscope device is the necessary troubleshooting equipment for encoders and will provide a graphical representation of the output signal.