Hello, I always had this problem. I update Indi/Ekos/Kstars by the PPA. See some logs, from the robofocus tab, I remove some line in double ... if it can help ...
2016-07-10T14:37:04: ReadUntilComplete with timeout 15 2016-07-10T14:37:03: Bogus position: FD005444 2016-07-10T14:37:03: TTY error detected: Timeout error 2016-07-10T14:36:48: ReadUntilComplete with timeout 15 2016-07-10T14:36:47: Bogus position: FD005444 2016-07-10T14:36:47: TTY error detected: Timeout error 2016-07-10T14:36:32: ReadUntilComplete with timeout 15 2016-07-10T14:36:31: Bogus position: FD005444 2016-07-10T14:36:31: TTY error detected: Timeout error 2016-07-10T14:36:16: ReadUntilComplete with timeout 15 2016-07-10T14:36:15: Bogus position: FD005444 2016-07-10T14:36:15: TTY error detected: Timeout error 2016-07-10T14:36:00: ReadUntilComplete with timeout 15 2016-07-10T14:35:59: Bogus position: FD005444 2016-07-10T14:35:59: TTY error detected: Timeout error 2016-07-10T14:35:44: ReadUntilComplete with timeout 15 2016-07-10T14:35:43: Bogus position: FD005444 2016-07-10T14:35:43: TTY error detected: Timeout error 2016-07-10T14:35:28: ReadUntilComplete with timeout 15 2016-07-10T14:35:27: Bogus position: FD005444 2016-07-10T14:35:27: TTY error detected: Timeout error 2016-07-10T14:35:12: ReadUntilComplete with timeout 15 2016-07-10T14:35:11: Bogus position: FD005444 2016-07-10T14:35:11: TTY error detected: Timeout error 2016-07-10T14:34:56: ReadUntilComplete with timeout 15 2016-07-10T14:34:55: Bogus position: FD005444 2016-07-10T14:34:55: TTY error detected: Timeout error 2016-07-10T14:34:40: ReadUntilComplete with timeout 15 2016-07-10T14:34:39: Bogus position: FD005444 2016-07-10T14:34:39: TTY error detected: Timeout error 2016-07-10T14:34:24: ReadUntilComplete with timeout 15 2016-07-10T14:34:23: Bogus position: FD005444 2016-07-10T14:34:23: TTY error detected: Timeout error 2016-07-10T14:34:08: ReadUntilComplete with timeout 15 2016-07-10T14:34:07: Bogus position: FD005444 2016-07-10T14:34:07: TTY error detected: Timeout error 2016-07-10T14:33:52: ReadUntilComplete with timeout 15 2016-07-10T14:33:52: Focuser is moving to position 5441 2016-07-10T14:33:52: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X34 0X31 0XFFFFFFB8) 2016-07-10T14:33:52: Moving... with buf[0]=(I) 2016-07-10T14:33:52: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X34 0X31 0XFFFFFFBB) ... 2016-07-10T14:33:49: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X34 0X34 0XFFFFFFBB) 2016-07-10T14:33:49: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:48: ReadUntilComplete is complete. Bytes read: -1075482776 2016-07-10T14:33:48: buf[0]=0X46 2016-07-10T14:33:48: ReadUntilComplete with timeout 15 2016-07-10T14:33:48: Focuser is moving to position 5444 2016-07-10T14:33:48: Checksum: Wrong (IIIIIIIII,9), 48 != 49 2016-07-10T14:33:48: RES (0X49 0X49 0X49 0X49 0X49 0X49 0X49 0X49 0X49) 2016-07-10T14:33:48: Moving... with buf[0]=(I) 2016-07-10T14:33:47: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X34 0X34 0XFFFFFFBE) ... 2016-07-10T14:33:45: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X35 0X33 0XFFFFFFBB) 2016-07-10T14:33:44: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:43: ReadUntilComplete is complete. Bytes read: -1075482776 2016-07-10T14:33:43: buf[0]=0X46 2016-07-10T14:33:43: buf[0]=0X4F 2016-07-10T14:33:43: buf[0]=0X4F 2016-07-10T14:33:43: buf[0]=0X4F 2016-07-10T14:33:43: ReadUntilComplete with timeout 15 2016-07-10T14:33:43: Focuser is moving to position 5453 2016-07-10T14:33:43: Checksum: Wrong (OOOOOOOOO,9), 78 != 4f 2016-07-10T14:33:43: RES (0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F) 2016-07-10T14:33:43: Moving... with buf[0]=(O) 2016-07-10T14:33:43: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X35 0X33 0XFFFFFFBE) ... 2016-07-10T14:33:40: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X34 0X31 0XFFFFFFB8) 2016-07-10T14:33:40: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:39: ReadUntilComplete is complete. Bytes read: -1075482776 2016-07-10T14:33:39: buf[0]=0X46 2016-07-10T14:33:39: buf[0]=0X49 ... 2016-07-10T14:33:39: buf[0]=0X49 2016-07-10T14:33:39: ReadUntilComplete with timeout 15 2016-07-10T14:33:39: Focuser is moving to position 5441 2016-07-10T14:33:39: Checksum: Wrong (IIIIIIIII,9), 48 != 49 2016-07-10T14:33:39: RES (0X49 0X49 0X49 0X49 0X49 0X49 0X49 0X49 0X49) 2016-07-10T14:33:39: Moving... with buf[0]=(I) 2016-07-10T14:33:39: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X34 0X31 0XFFFFFFBB) ... 2016-07-10T14:33:36: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X36 0X38 0XFFFFFFC1) 2016-07-10T14:33:36: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:35: ReadUntilComplete is complete. Bytes read: -1075482776 2016-07-10T14:33:35: buf[0]=0X46 2016-07-10T14:33:35: buf[0]=0X4F ... 2016-07-10T14:33:35: buf[0]=0X4F 2016-07-10T14:33:35: ReadUntilComplete with timeout 15 2016-07-10T14:33:35: Focuser is moving to position 5468 2016-07-10T14:33:35: Checksum: Wrong (OOOOOOOOO0X4*30 0X30 0X35 0X3,32), 78 != 4f 2016-07-10T14:33:35: RES (0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F) 2016-07-10T14:33:35: Moving... with buf[0]=(O) 2016-07-10T14:33:34: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X36 0X38 0XFFFFFFC4) ... 2016-07-10T14:33:31: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X34 0X38 0XFFFFFFBF) 2016-07-10T14:33:31: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:30: ReadUntilComplete is complete. Bytes read: -1075482776 2016-07-10T14:33:30: buf[0]=0X46 2016-07-10T14:33:30: buf[0]=0X4F ... 2016-07-10T14:33:30: buf[0]=0X4F 2016-07-10T14:33:30: ReadUntilComplete with timeout 15 2016-07-10T14:33:30: Focuser is moving to position 5448 2016-07-10T14:33:30: Checksum: Wrong (OOOOOOOOO,9), 78 != 4f 2016-07-10T14:33:30: RES (0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F 0X4F) 2016-07-10T14:33:30: Moving... with buf[0]=(O) 2016-07-10T14:33:30: CMD (0X46 0X47 0X30 0X30 0X35 0X34 0X34 0X38 0XFFFFFFC2) 2016-07-10T14:33:30: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X32 0X38 0XFFFFFFBD) ... 2016-07-10T14:33:11: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X32 0X38 0XFFFFFFBD) 2016-07-10T14:33:11: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:10: Session log file /tmp/indi_robo_focus_2016-07-10T14:31:13.log 2016-07-10T14:33:10: Toggle Logging Level -- Driver Debug 2016-07-10T14:33:10: RES (0X46 0X44 0X30 0X30 0X35 0X34 0X32 0X38 0XFFFFFFBD) 2016-07-10T14:33:10: CMD (0X46 0X47 0X30 0X30 0X30 0X30 0X30 0X30 0XFFFFFFAD) 2016-07-10T14:33:10: Toggle Debug Level -- Driver Debug 2016-07-10T14:33:08: Debug is enabled. 2016-07-10T14:32:24: Device configuration applied. 2016-07-10T14:32:24: Backlash is now 0 2016-07-10T14:32:24: Motor settings are now 1 1 1 2016-07-10T14:32:24: Loading device configuration... 2016-07-10T14:32:23: Robofocus is online. Getting focus parameters...