Ebyte E840-TTL-4G02E User Manual page 20

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cannot be enabled, and in the high-speed mode, the short message transmission and reception function is not
supported. Only the first Socket effective link is valid, and the protocol distribution data is not supported.
After the EBYTE cloud transparent transmission function is enabled, the high-speed mode is invalid.
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When the device serial port outputs the words "pdp error, device will be reset!", it indicates that the PDP
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context is disabled by the network. The SIM card may be loose or the current network channel is occupied
abnormally.
The SMS function needs to insert the SIM card to support the SMS service. The IoT card cannot send and
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receive SMS messages. When the device sends a text message, the device responds with OK only to indicate
that the module has sent the SMS, which does not mean that the device has received the SMS.
After modifying the serial port break time, the AT command must be configured according to the frame break
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time. For example, after setting the parameter to 2000ms, you need to configure the device parameters after
power-on. You need to send '+++'. , Send a valid AT command within the period of more than 2000ms and
less than 3000ms to enter the AT mode normally.
The network AT command will fail in high speed mode.
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E840-TTL-4G02E User Manual
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