How to connect an encoder to a PLC? Requirements for servomotors with high resolution

Welcome,

I would like to know the answers to some questions that are bothering me. I am a technical school student, so please forgive me if something seems pointless to you, but I would like to learn and understand

I have a question about servo motors and the connection of their encoders to the PLC. At the company where I had an internship I saw large servos together with encoders. These are supposedly characterised by an extremely detailed "resolution" of the angle of rotation reading. In such cases, when the angle reading is very dynamic and detailed, is it necessary to use some special inputs of the PLC with a higher signal reading frequency (here from the encoder)? If so:
- What are such inputs called/designated?
- Are they generally available in the original version of controllers, e.g. S300, or do you have to equip yourself with specialised modules?
- What are the differences in the "encoder readout frequency" of such special inputs vs. normal analogue inputs(or discrete inputs?)To what extent do they differ?

Thank you in advance for your help, and best regards to all forum members!

http://www.download.labster.com.pl/AK58_EN.pdf

Generally when it comes to encoders for servo motors, these encoders are connected directly to the input on the servo amplifier (controller). The changes are so fast that no controller can comprehend such a number of pulses. A Mitsubishi servo, for example, has over 130,000 points per revolution.

Special counting modules are dedicated to the controllers, which usually operate in pulse counting mode or pulse frequency measurement mode. At the output of such modules, we usually have programmable binary outputs. Counters can return a hexadecimal value to the PLC, generate a pulse train (PTO), solutions abound.

- What are such inputs called/tagged?
Usually they are counter inputs, i.e. inputs where there is no transient, the output does not hang in the air, as with OCs.

- Are they generally available on the original version of controllers, e.g. S300, or do you have to equip yourself with specialised modules?
Yes, specialist modules are used to control servo motors.

- What are the differences in the 'encoder readout frequency' of such specialised inputs versus normal analogue inputs(or discrete?)To what extent do they differ?
I will focus on encoders with TTL or HTL (discrete) standard outputs. The signal from such an encoder is no different apart from the high pulse frequency (quadrature). The whole philosophy is that the pulse duration must be longer than the cycle time of the control programme.