Ebyte E810-DTU User Manual

Also see for E810-DTU: User manual User manual User manual User manual User manual

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Ebyte E810-DTU User Manual Manual pdf 14 page image

Ethernet to 485/232 E810-DTU User ManualCopyright ©2012–2017，成都亿佰特电子科技有限公司 135.3. Heartbeat mechanismIn the network transparent transmission mode, users can make the module send heartbeat packets to the server. Heartbeat packets can be sent to the web server or sentto the serial device, they cannot run at the same time.Network heartbeat pocket: The heartbeat packet is sent to the network, in the heartbeat transmission cycle, the module sends heartbeat packet data to the networkserver to maintain the connection with the network server. It only runs in the TCP Client and UDP Client modes。Serial data packet: In the set heartbeat sending cycle, the module sends heartbeat packet data to the serial port, users can do corresponding processing after the serialport receives the heartbeat data.In an application in which a server sends a fixed inquiry command to a device, in order to reduce communication traffic, users can choose to send a heartbeat packet(inquiry command) to the serial device side instead of sending a inquiry command from the server.User-defined data packet defaults to hexadecimal data (ASCII code optional), E810-DTU module supports custom heartbeat packet content up to 40 bytes.5.4. Overtime restartOvertime restart (no data restart) function is mainly used to ensure long-term stability of E810-DTU. When the network port cannot receive data for a long time, or ifthe network does not receive data for a long time, the E810-DTU will restart after exceeding the set time, thus avoiding the influence of abnormal conditions on thecommunication. The normal working time of this function is set to 60~65535S, default 300S. When the setting time is less than 60S, the default setting is zero, that is, thefunction is turned off.5.5. TCP multi-connection functionTCP multi-connection function is mainly to solve that in the TCP Sever mode, the user has multiple clients to connect E810-DTU and send and receive data at the sametime. When E810-DTU is used as a TCP Server, up to 6 connections can be established at the same time, the TCP Server sends data to multiple (up to 6) TCP clients on theconnection at the same time. When the number of established connections exceeds six, the connection established at the beginning will be actively disconnected, that is, theold connection will be kicked off.5.6. Clearing cached dataWhen the TCP Client connection is not established, the data received by the serial port will be placed in the buffer area, the E810-DTU serial port receive buffer is 400bytes. When the connection is established, the serial port buffer data can be set whether to clear according to customer needs.5.7. Link and data transfer instructionsLink indicates the network connection status of the module. In TCP mode, when the network is not connected, the link goes out. When the connection is established,the link is always on. Link indicator is on in UDP mode.The other is the data transmission indication, which shows the data transmission status of the serial port of the module. When there is no data transmission on the serialport, the data transmission indicator is extinguished. When there is data transmission on the serial port, the flashing indicates that the period is 60ms and the indicator lit10ms.