Hello friends,

TTL and HTL output signals are two different electrical standards used by rotary encoders to transmit position information to control systems. Both generate digital pulses, but differ mainly in voltage levels and application suitability.

▪︎ TTL (Transistor-Transistor Logic): Typically operates at +5V for logic HIGH and 0V for logic LOW. Offers fast response and low power consumption, but is sensitive to noise and signal loss over long cable distances.

▪︎ HTL (High Threshold Logic): Usually works at +24V for logic HIGH and 0V for logic LOW. Provides better signal integrity over long distances and is more resistant to interference, but consumes more power and responds slightly slower.

Selecting the right output type depends on your system's requirements. TTL is ideal for short, fast, and low-power applications, while HTL suits industrial environments with long cables and electrical noise.

Bottom line: If the encoder outputs 5V, it's TTL. If it outputs 24V, it's HTL. TTL is fast but delicate. HTL is tough but slower. The animation above shows you how A/B pulses differ in voltage level while their logic remains the same.

And remember: choosing the wrong signal type can lead to data loss or system failure.

Related links:

+ Back to Encoders Main page

+ Encoder Output types

+ Encoder Controller

+ Plc System for encoder

+ Servo Systems

+ VFD main page -