To use a 24vdc to the step or direction inputs, use a 2.247 kOhm resistor in series with the Step+ and Dir+ input (pins 1 & 2). This will be in addition to the 243 Ohm resistors inside the drives. This resistor will drop the voltage and limit the current to 5vdc and 9.6mA. Add nothing for S- and D-.
For a 24vdc to use with the Shutdown+ (pin 16), add 3.639 kOhm; same for Reset+ (pin 11). This also goes for the Remote Input (pin 16) on the OEM750; and the Gear Shift Input (pin11) on the OEM750 and E-DC drives.
It may be possible to add these resistors inside the drive as a custom product to reduce machine part count or reduce points of contact that may potentially fail. Please contact your local Parker ATC for a quote on customer product. The E-AC drive with this Standard Custom modification is p/n: CS*E-AC-24V-12785 and can be ordered over the Extranet.