I use a modem with an SL6087 chip, to update a file on a FTP server.
I wrote some C code to control the modem on an RS232 using an USB-to-RS232 cable.
My code works most of the time, but on some instance, the command “AP+WIPCREATE=4,1,,,” returns “+CME ERROR: 803”.
When I have this error, I close and restart the bearer and it works again.
The manual defines this error as “operation not allowed in the current Internet Library stack state”.
So my questions are:
- What could cause this error?
- How to stop it from happening?
- When it happens, is there another way to restore rather than closing and restarting the bearer?