Forum is back, good news !
Thank you for your answers (nickrose & jfcharles), i think my problem came from a cable defective, it works great with another device but not with Eclipse. The Eclipse seems very sensitive to the quality of the midi signal. Besides, i think now used a "star connection" with a midi thru-box to avoid losses of a connection "in" -> "thru" -> "in" -> "thru".
nickrose: i program a "remote control" for the eclipse (C#). is it possible to use the document "Eventide Harmonizer MIDI SysEx Reference Manual, v0.90" ?, this document is update ?
Thank You very much (and excuse me for my bad English…)