Sustain pedal S 30 synth

by Ragnar
(Norway)

I bought a pedal to my Yamaha S 30 synth. It looks like the FC 3 pedal. Unfortunately no information is visible on the pedal. Anyway, it does not work, it rather gives the opposite effect than sustain. I have put the pedal in the foot switch on the synth and I chose the utility option "CTRL Other> FS 64(sustain)". Any suggestions as to what I can do to check it out?