Roland System 100m

I've been using my Kenton Pro Solo II for a while now -- just got around to studying the 
manual (again, trying to get clock divide right) --

In any case -- it says

"- you can select the following types for the GATE output;

Gate V-Trig low (+5v)    [g, middle LED bar]
Gate V-Trig high (+15v)  [g, upper LED bar]

Gate is the most common signal used for telling a synth when to play its note. The high 
level  Gate is suitable for most synths, such as Roland, SCI, ARP, Oberheim. The low level 
gate may  be needed for synths that require a lower gate voltage such as the SH-101."

What's the proper gate V for the 100M?  If I've been using 15V at times, is that OK (no 
harm done)?