[Protocol]：IPv4、TCP/UDP、HTTP、MQTT
[Interface]：TTL(3.3V)、Ethernet port (RJ45)
[Size]：17 x 19 x 4mm（length x width x height）
[Weight]：1.6g ± 1g
[Introduction]：NS1 is a serial server that realizes serial data ⇌ Ethernet data conversion;It has a variety of Modbus gateway modes and MQTT/HTTP IoT gateway modes, which can meet the networking functions of various serial devices.
| Serial number | Pin screen printing | Pin function | description |
| 1 | RX_P | RX_P | Ethernet receives RX+signals |
| 2 | RX_N | RX_N | Ethernet receives RX-signals |
| 3 | TX_P | TX_P | Ethernet sends TX+signal |
| 4 | TX_ N | TX_ N | Ethernet sends TX signal |
| 5 | D+ | NC | Default hanging |
| 6 | D- | NC | Default hanging |
| 7 | TXD0 | TXD0 | Serial port sends data, TTL level communication voltage only supports 3.3V, if connected to 5V, level conversion is required |
| 8 | PB6 | RTS | Modem output signal of serial data, requesting transmission |
| 9 | PB5 | NC | Default hanging |
| 10 | RXD0 | RXD0 | Serial port receives data, TTL level communication voltage only supports; 3.3V, if connected to 5V, level conversion is required |
| 11 | PB3 | 485_EN | RS485 enable control pin, set high when the serial port sends data, and set low in normal state |
| 12 | PB2 | NC | Default hanging |
| 13 | PB1 | NC | Default hanging |
| 14 | PB0 | CTS | Modem input signal of serial data, clear transmission |
| 15 | RST | RST | External reset input, effective at low level |
| 16 | PB22 | NC | Default hanging |
| 17 | PB21 | LED2 | 4hz square wave output within 3 seconds after power-on Network not connected: output high level Network connected: output low level |
| 18 | PB20 | LED1 | 4hz square wave output within 3 seconds after power-on The network cable is not connected: output 5hz square wave Network cable connected: but not connected: output 1hz square wave Network connection succeeded: output 0.33hz square wave When the serial port has data receiving and sending, output 60ms pulse low level |
| 19 | ON | NC | Default hanging |
| 20 | PA4 | IO_RST | To restore the factory pins, it is necessary to connect the reset button externally, and the low level is valid for about 5s |
| 21 | PA5 | NC | Default hanging |
| 22 | PA15 | TX_LED | Serial port sending indicator output, 4hz square wave output within 3 seconds after power-on The default output is high level. When there is data output, the output is low level. When there is data continuously, the output period is 80ms, and the low level is 20ms square wave signal |
| 23 | GND | GND | Common grounding terminal, power supply negative terminal input |
| 24 | VCC | VCC | Positive power input, supporting 3-5.5V input |
| 25 | GND | GND | Common grounding terminal, power supply negative terminal input |
| 26 | PA14 | RX_LED | Serial port receiving indicator output, Output 4hz square wave within 3 seconds after power-on, The default output is high level. When there is data input, the output is low level. When there is continuous data, the output period is 80ms, and the low level is 20ms square wave signal |
| 27 | PA13 | NC | Default hanging |
| 28 | PA12 | NC | Default hanging |
| 29 | NC | NC | Default hanging |
| 30 | NC | NC | Default hanging |
| 31 | PB9 | LINKLED | After inserting the network cable, output low level, and output high level when the network cable is not connected |
| 32 | PB8 | SPDLED | SPD indicator |
| 33 | TCK | NC | Default hanging |
| 34 | TIO | NC | Default hanging |
| 35 | NC | NC | Default hanging |
| 36 | GND | GND | Common grounding terminal, power supply negative terminal input |