- The Differences in these Devices will be obvious once document is reviewed. You may right click and *Save As* or simply open them if PDF Reader is Integrated with you Browser.
- 26LS31 PDF, 26LS32 PDF, DS3486 PDF, DS3487 PDF, DS9637 PDF, DS9638 PDF, 74HCT86 PDF.
- This page includes RS-422 Encoder Interfacing Schematics for Absolute Encoders, as well as converting Gray Code Encoders to Natural Binary Interface.
- Converting Gray Code to Binary using XOR Gates provides one with the function of being able to change direction increase counting. i.e. Change count direction for CW increase count to CCW Increase count. Several Manufactures provide this function when purchasing Absolute Binary Encoders.......but at a great price increase over the equivalent Gray Code Absolute Encoders. Please NOTE..... without EXCEPTION, ALL Absolute Encoders start out using Gray Code, thus the higher cost for Natural Binary, and you can do it for very, very small cost.
- For further details please see this Schematic:
This image is rather large but will allow you to print it as a full 11 X 8.5 inch page. Note single line(+5V or grnd) to change increasing count direction to either CW or CCW. This is done by using a simple 74HCT86 device and switching a single pin 12 high or low. - Realize that Absolute Encoders produce a single ended line output, whether Gray Code or Binary. Therefore it is strongly recommended that all lines be convert to RS-422 to allow very long runs of lines, plus eliminate introduction of noise on the lines. There are several device, or line drivers and receivers that do this very nicely and very small component cost. I personally have used all the devices listed, but do prefer the 26LS31 and 26LS32 devices because they are a very rugged device electrically. These can be purchased as CD (CMOS), 26CD32/31 devices but I have not used them for above reasons.
- For those who have Natural Binary and wish to apply RS-422 Line Drivers and Receivers this is a schematic for such application:
Keep in mind that one of these Schematics represents 12 Bit Encoders, but can very easily be increased/decreased to 8Bit, 12Bit, 14Bits, or 16Bits. As time permits I will upload all Schematic and PCB Artwork for those projects I have completed for others.........so please bear with me Folks. For the time being I will leave the rest of this page blank and available. At the bottom of this page please find the PDF documentation for these devices.
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Amateur Radio Station VE1ALQ & VE9DW |
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VE1XYL
when allowed ( ;o} 