SMDT IoT-3399E, User Manual, Page: 14 / 24

Shenzhen
Smart Device Technology Co.,Ltd
◆
232 Serial port interface*2
Led out of the two sets of ordinary 232 serial port, can support the general market of the 232 serial
devices.
Remark
：
1.Serial voltage matching, Cannot access directly TTL,485 serial device.
2.TX
，
RX whether the connection is correct.
NO. Definition Property Description
1 GND ground electrode ground electrode
2 232-RXn input 232-RX
3 232-TXn output 232-TX
4 VCC Power supply 5V output
◆
TTL Wires Serial Socket Port*1
The board raises a common one wires of serial ports,can support general serial port devices on the
market
，
level of the serial port is 0V to 3.3V.If the abutting serial level higher than 3.3 V
，
must have the
isolating circuit or level conversion circuit, otherwise it will burn out master and equipment.
Notice
：
1.If TTL serial port voltage can match or not, can't directly access MAX232,485 devices.
2.TX
，
RX connection if is correct.