
4. MATTERS COMMON TO BOTH LCD--MOUNTED TYPE
AND STAND--ALONE TYPE i SERIES (HARDWARE)
B--63005EN/02
384
With a CNC machine tool, three ground systems are used.
(1) Signal ground system (SG)
Signal ground (SG) provides a reference voltage (0 V) for the electric
signal system.
(2) Frame ground system (FG)
The purposes of frame ground (FG) are to ensure safety and to provide
shielding from external and internal noises. Specifically, the frames
of equipment, unit cases, panels, inter--unit interface cables, and so
forth are shielded.
(3) Protective earth (PE)
The protective earth (PE) is designed so that the protective grounds
provided between the units are connected to ground at one point from
a system point of view.
4.8.2
Grounding