[Gammu - 1.07.00 built 15:13:46 Aug 7 2006 in gcc 3.4] [Connection - "dku5"] [Model type - "3100"] [Device - "/dev/ttyUSB0"] [Run on - Linux, kernel 2.6.17-gentoo-r4] [Module - "1100|1100a|1100b|2650|3100|3100b|3105|3108|3200|3200a|3220|3300|3510|3510i|3530|3589i|3590|3595|5100|5140|5140i|6020|6021|6100|6111|6170|6200|6220|6230|6230i|6310|6310i|6385|6510|6610|6610i|6800|6810|6820|7200|7210|7250|7250i|7270|7600|8310|8390|8910|8910i"] [ERROR 9: Error setting device DTR or RTS.] [Closing]
Sorry, but I think dku5 is not supported on linux. Furthermore, judging after http://avr.auctionant.de/ark3116_linux_driver/, the ark3116 driver don't give access to control lines like DTR or RTS (see bad news in the above mentioned URL). Closed as UPSTREAM.
Try gnokii I have Nokia 3100 with DKU5 cable, recognized by ark3116 driver. gammu fails with that exactly message. gnokii works, though.
I have then tried gnokii to upload and download files, but without success.