A new series of incremental rotary encoders made by Heidenhain Corp., the
ROD 466 and ERN 460, permit PLC manufacturers to reduce cost by using 24V power
supplies in new and existing generations of controls. Typically, 24V power
supplies are less expensive than 5V power supplies designed for use with sensors
and encoders. Furthermore, most controls come with 24V supplies to drive the
rest of the machine-tool interface.
Signal output from the ROD 466 and ERN 460 is TTL-compatible. Because this interface permits the use of high transmission frequencies across long cables, Heidenhain maintains that it can be extremely useful in many large machine-tool applications.
Both the ROD 466 and ERN 460 are available in line counts from 40 to 10,000 lines/revolution. By employing integrated electronics, it becomes possible to realize resolutions as great as 40,000 pulses per revolution.
The encoders' signal output is 5V TTL quadrature output with fault-error detection and reference-mark evaluation. Acceptable unit operating temperature ranges from 32 to a maximum of 158F.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.