This topic describes the common questions about processing data point (DP) data to help you troubleshoot problems with DP data receiving and sending.
What is the recommended DP data reporting interval?
- If you develop with the MCU SDK solution, the MCU can report data when DP status changes. Reporting duplicate data is not recommended. If duplicate reporting is necessary, do not set the reporting interval to less than one second.
- Except for the raw data, the SDK filters out identical DP data that has been reported. If you want to use the advanced syntax to set the filtering rule, submit a service ticket.
- To report multiple DPs at the same time, you can use the command
0x07 to allow the MCU to send data units of multiple DPs in one packet. For more information, see Report status.
Can the MCU handle the serial data stream if the cloud sends data of multiple DPs in one packet?
- The module can group the received data into packets and transmit a packet every 40 ms.
- The serial protocol enables full-duplex communication to avoid packet loss. You can allow the MCU to wait for 60 ms after receiving a packet to determine if this is the last one. This way, the MCU will handle the serial data after the transmission ends.
The raw and string data is limited to 256 bytes. How can I change the length limit?
- Generally, DP data is limited to 256 bytes. The default transmission channel in the cloud supports a data size of more than 1 KB. The serial buffer can hold up to 1 KB.
- Except for the Espressif based modules, the serial buffer for raw data can be up to 1 KB. Raw data is not subjected to the size limit of 256 bytes.
- For the string data, the cloud specifies a limit of 255 bytes, which cannot be changed.