TB6600 Stepper Motor Driver SKU DRI0043 - Input current limiting resistor

Hi,

I would like to control an TB6600 Stepper Motor Driver SKU DRI0043 using 24Vdc signal inputs. The store where I bought the module says this is possible, however I found in the pdf manual that;

Common-Anode Connection: Connect PUL +, DIR + and EN + to the power supply of the control system. If the power supply is + 5V, it can be directly connected. If the power supply is more than+5V, the current limiting resistor R must be added externally. To ensure that the controller pin can output 8 ~ 15mA current to drive the internal optocoupler chip.

Common-Cathode Connection: Connect PUL -, DIR - and EN - to the ground terminal of the control system

6. FAQ

1. 

Q: If the control signal is higher than 5V, how do I connect? 

A: You need add a resistor in series

I wish to connect the system by the common cathode method. Does this mean that I do not need the limiting resistor?

If I do require the limiting resistor, how do I calculate the ideal resistor value and power rating required? And is this a resistor per input signal, i.e. one on DIR+, PUL+ and EN+?

Am I assuming standard ohms law will calculate the required value;

24V / 12mA = 2K @ 1/2W would be ok?

Thanks.