Hello Christian,
There is no handshaking in the zmodem file transfer. The sz command causes the OLA output the file to USB (or the TX pin) in zmodem format - without checking if anything is “listening” for the data. The transfer will always complete…
Please try:
Connect the OLA to your computer via USB
Open Tera Term - using the USB COM port
You should see the sensor data being logged to SD card
Press a key to open the menu
Select the file transfer menu
Use ls to list the files
Use sz filename to start the zmodem file transfer
You then have 20 seconds to put Tera Term into zmodem receive mode
If all is well, you should see the green progress bar increase. The window will close when the transfer is complete.
Please do not connect anything to the TX and RX pins.
Please do not configure the TX and RX pins for the terminal.
Please do everything through Tera Term, connected via USB only.
I hope this helps,
Paul