Hi,
I’ve found solution. There was similar problem with SL6087 mentioned in this topic: https://forum.sierrawireless.com/t/sl6087-firwmare-upgrade-failed-with-xmodem-binary/9036/1
Using WOPEN=4 command to erase the binary from memory helped with upgrade.
So my procedure was (I had firmware 7.51 installed):
- update botloader
- restart modem
- check if modem response with AT
- WOPEN=4
- check if modem response with AT
- “AT+WDWL”
- send file with XMODEM