Data Sheet

RS232/485 TO ETH User Manual
5/22/19 www.waveshare.com/wiki 14 / 21
2.4. FEATURES
2.4.1. IDENTITY PACKET FUNCTION
Identity packet is used for identifying the device when RS232/485 TO ETH works as TCP
client/UDP client. There are two methods to send identity packet.
⚫ Identity packet will be sent after connection is established.
⚫ Identity packet will be added on the front of every data package.
Identity packet can be MAC address or user editable identity packet. User editable identity
packet should less than 40 bytes.
2.4.2. HEARTBEAT PACKET FUNCTION
Heartbeat packet: RS232/485 TO ETH will output heartbeat packet to serial side or network
side periodic. User can configure the heartbeat packet data and sending interval. Serial
heartbeat packet can be used for polling Modbus data. Network heartbeat packet can be used
for showing connection status and keeping the connection (only take effect in TCP/UDP Client
mode).
2.4.3. NON-PERSISTENT CONNECTION
RS232/485 TO ETH support non-persistent connection function in TCP Client mode. When
RS232/485 TO ETH adopts this function, RS232/485 TO ETH will connect to server and send data
after receiving data from serial port side and will disconnect to server after sending all the data
to server and no data from serial port side over 3s.
2.4.4. MODBUS GATEWAY
Modbus gateway includes: Modbus RTU transparent transmission, Modbus ASCII
transparent transmission, Modbus RTU<=>Modbus TCP protocol conversion, Modbus polling and
serial port query.
Figure 12 Identity Packet application diagram