JF TECH JRC-27F - Front-End Device Grounding Importance

E. AB line voltage between the decoder requires less than 5V.
2.7.4 Front-end device requires grounding
Poor grounding may cause the chip to burn.
2.7.5 Any type of alarm input
The alarm output unit interface is a normally open type.
8 external alarm interface schematic:
(1) Alarm input 1,2,3,4
(2) Ground
(3) RS232 serial interface to send and receive
(4) RS485 interface
(5) alarm inputs 5,6,7,8
(6) Ground
(7) alarm output
16 External alarm interface schematic:
① ⑥⑧ alarm input ②⑦ ground ③ alarm output RS485④RS232
Parameters
Meaning
G
GND
R、T
Send and receive serial interface
A、B
485 communication interface
2.7.6 Alarm Input Port Description
8/16 channel alarm input, input type limitation (can be normally open or normally
closed);