EC200A-EU Bad flow control during transfer using USB virtual AT port

IoT Modules LTE Standard Module
1

Hi,

We are currently trying out the EC200A-EU modem using the LTE OPEN EVB kit. The firmware of the modem is EC200AEUHAR01A27M16_01.200.01.200.

We are trying USB virtual AT port, and tried to transfer a 1MB file to UFS using ‘AT+QFUPL’.
The file doesn’t transfer all bytes, it looks like a flow control error. But if we wait 1 second between every 1KB of data transfered, the file is transfered properly without missing data.

The transfer was tried on different environments with the same behavior:

  • using standard serial terminal, or using a script with pyserial.
  • on windows and linux (with quectel driver installed on both).

Is it expected to not have flow control on USB virtual AT port? I was under the impression that the USB should handle it automatically. Is there some other steps needed that we’re missing?

Best regards,

Guillaume

2

Please confirm whether the remaining space is sufficient

image
image858×225 19.1 KB

3

Thanks for your reply,

Yes I still have enough space. More than 3MB free with only a 1MB file transfer. As I said it works properly with “slow” transfer.

AT+QFLDS="UFS"
+QFLDS: 3747840,4980735