LP3500 and KDU keyboard - Display

I’m interfacing the KDU keyboard - display with the LP3500 SBC. From the users manual it appears you need to use Digital outputs 0-6 to run the 7 LEDs on the display unit.

I plan on connecting K to my raw power of about 18 VDC. Will there be any issue driving the display LEDs with this voltage via the digital outputs.

Based on the users manual I’m 90% sure that the Key board buttons are sensed through LP3500 display interface J9. Anyone know anything different?

Thanks in advance!