IO link sensors with PLC
An IO-Link system consists of an IO-Link master and one or more
IO-Link devices

That's a quote from Wikipedia IO-Link and basically it means that master and slaves have to be compatible: -

An IO-Link system consists of an IO-Link master and one or more
IO-Link devices, i.e. Sensors or Actuators. The IO-Link master
provides the interface to the higher-level controller (PLC) and
controls the communication with the connected IO-Link devices.


When using IO link technology with a PLC (siemens s7-1200) can you
connect devices that are not IO link sensors?

No, you can't.

For example say I wanted to connect an existing normal push button to
a IO link master, is it possible to cut the plug of the IO link cable
and connect the button with the 3 required cores( positive, negative
and the signal wire)?

No, you can't.