I found out that the previous owner had replaced the spindle motor and this one has inside a MZ sensor although the old one had a M sensor, because the plans I have state this.
I checked the cable of MZ sensor and the only problem I found was that the shield is not connected to earth directly, but to pin 10 of the JY2.
I checked the parameters and as far as can judge seem ok.
I can not understand what that would be to trigger the alarm of X-axis communication even if it seems that is something with the spindle orientation.
I checked the pulse coder cable, OK.
I added a cable to ground from the replaced MZ sensor (the machine originaly had a M sensor in the spindle motor).
This way the alarm hasn't appeared yet.
Let's see.....