问题描述
在libusb-0.1和libusb-1.0中都看不到任何setter RTS/DTR函数.我应该使用usb_control_msg()发送smth special吗? USB设备是CDC设备(不是FTDI)
I can't see any setter RTS/DTR functions in both libusb-0.1 and libusb-1.0. Should i send smth special using usb_control_msg() ? usb device is CDC-device (not FTDI)
推荐答案
libusb本身不能做到这一点-您应该为CDC设备发送控制状态"，或者为FTDI设备发送特定于FTDI的命令.
libusb can't do that itself - you should send 'control state' for CDC-device or FTDI-specific commands for FTDI-device.
对于CDC: http://cscott.net/usb_dev/data/devclass/usbcdc11.pdf
`6.2.14 SetControlLineState该请求生成RS-232/V.24样式的控制信号....
`6.2.14 SetControlLineStateThis request generates RS-232/V.24 style control signals....
D1半双工调制解调器的运营商控制.该信号对应于V.24信号105和RS-232信号RTS. 0-停用载波 1-激活运营商在全双工模式下，设备会忽略该位的值
D1 Carrier control for half duplex modems. This signal corresponds toV.24 signal105 and RS-232 signal RTS. 0 - Deactivate carrier 1 - Activate carrierThe device ignores the value of this bit when operating in full duplex mode
D0指示DCE是否存在DTE.该信号对应于V.24信号108/2和RS-232信号DTR. 0-不存在 1-现在`
D0 Indicates to DCE if DTE is present or not. This signal corresponds to V.24signal 108/2 and RS-232 signal DTR. 0 - Not Present 1 - Present`
PS.感谢libusb-devel邮件列表中的Xiaofan.
PS. Thanks to Xiaofan from libusb-devel mailing list.
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