An integrated single-output signal encoder for both multi-turn absolute encoder use and incremental encoder use

A new type of rotary encoder for application in AC servomotors is shown in this paper. It can be used as an incremental encoder (IE) or, with an external battery, can be used as a multi-turn absolute encoder (MAE). In either case it has a common, single-output signal. It consists of a low-current IE, a 24-bit CMOS counter for multi-turn absolute data, and a serial data transmitter which sends a two-phase incremental signal, an index signal, pole sensor signals and a serial multi-turn absolute data signal. The advantages of this type of encoder are as follows: reduced wiring due to a single-output signal; common interface when used as an IE or as an MAE because of a unified single-output signal; common machinery when used as an incremental system or as an absolute system, if the machinery loads this type of encoder; and low cost MAEs, because this type of encoder consists of only one low-current IE and one IC