HIKVISION DS7208HVI-ST/SE

5.6. RS485 Module
 RS485 main control chip: SP491EEN, PIN 9, 10 were TX +,TX-,the
difference voltage close to 5 V
 TVS: B03NC (BA5/6/7/8), HK-4 (D2/3/4/5) protect the sending end (TX +,
TX-R +, R-)
 Thermistors (JK250) : JK250 (RPT1/2/3/4) protect the sending end (TX +,
TX-R +, R-)
 RS485 module part:
SATA interface
SATA
power
interface
B03NC
（
BA5/6/7/8
）
SP491EEN
JK250
（
RPT1/2/3/4
）
HK-4
（
D2/3/4/5
）
BD9329
（
U2
）