I am working with an industrial PLC, the Beckhoff BX9000, with 24 V digital outputs. I am looking to drive a hobby stepper motor with Polulu's 'A4988 Stepper Motor Driver Carrier', which accepts logic inputs with a max of 5.5 V. Will a simple voltage divider suffice to step down the 24 V clock signal to a 5 V clock signal to be input to the stepper driver? Or will issues occur?
Ya why not?
But maybe do other things like having an LDO to make sure that it is only 5V going to the motor and also check the current that the motor takes and if need have a limiter in there as well.
Of course your going to have issues, what they are depends on how you connect the whole thing up.
Probably not, because the general 24V PLC outputs don't provide pulse train output (PTO). Further the 24V outputs are slow, usually you need a special module that provides PWM, PTO,... on the PLC system.