FMM-101 is a miniature monitor module (a mere 1.3" (3.302 cm) H x 2.75" (6.985 cm) W x 0.5" (1.270 cm) D) used to supervise a Class B (Style B) circuit of dry-contact input devices.
X-NRI/EN-D Network Resource Interface is a universal interface of X-618 for external control access and audio extension. It is suitable to the needs of central interfaces management required by middle