Ebyte 400SL30-ETH, Руководство пользователя

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Chengdu Ebyte Electronic Technology Co., Ltd
E90-DTU(400SL30-ETH) User Manual
Copyright ©2012–2019, Chengdu Ebyte Electronic Technology Co., Ltd
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3.5.5
Short connection function
The use of TCP short connections is mainly to save server resources, and is generally applied to a multi-point scenario. With short
connections, you can ensure that the existing connections are useful connections and do not require additional controls for filtering.
The TCP short connection function is applied to the TCP Client mode. After the short connection function is enabled, the message
is sent. If there is no data reception in the serial port or network port within the set time, the connection will be automatically
disconnected. The short connection function is turned off by default, and the disconnection time can be set after the function is turned
on. The setting range is 2~255S.
3.5.6 KeepAlive function
Keep-Alive is the mechanism for detecting dead connections in a TCP connection. When the user does not send any data, the
"Keep-Alive" information is periodically sent on the TCP link to maintain the idle link, avoiding dead connections and consuming
unnecessary system resources. This setting is valid under TCP. Users can customize the Keep-Alive switch and other parameters.
keepalive parameter introduction
：
time
：
How many seconds after the TCP link does not receive data packet transmission to start the probe packet
；
intv
：
Time interval between the previous probe packet and the next probe packet
；
probes
：
The maximum number of probe failures. When the sniffing fails to this number, the TCP connection will be
disconnected.
。
3.5.7 Timeout restart function
The timeout restart (no data restart) function is mainly used to ensure that the E90-DTU-(400SL30-ETH) works stably for a long
time. When the network port does not receive data for a long time, or the network does not receive data for a long time,
E90-DTU-( The 400SL30-ETH) will restart after the set time has elapsed to avoid anomalies affecting communication. The timeout
timeout can be set through the webpage. The normal working time of this function is set to 60~65535S, and the default value is 3600S.
0 is off, when the setting is out of range, it returns to the default value.
3.5.8 Clearing the cache function
When the TCP connection is not established, the data received by the DTU will be placed in the buffer area. The
E90-DTU-(400SL30-ETH) receive buffer is 2Kbyte. When the TCP connection is established, the network cache data can be set or not
according to customer requirements.