They are commonly available on eBay for about US$20-$30. Also - FYI - I have had no issue with the MCS7840 adaptors (USB to 4-port RS232). So I am not saying every HL-340 based adaptor eve3ry produced will fail. The RS232 voltages are generated by a transceiver chip after the HL-340. I have had no problem with the PL2303 USB to Rs232 adaptors. But voltages are good from the PL2303 adaptors I have used. I then checked the RS232 data pins on an oscilloscope. I plugged in an alternative adaptor (using the PL2303 chip) and there was no problem. I know this because I bought some and could not get them to work. More specifically, they do not generate the correct voltage swings on the RS232 TxD pin. The HL-340 USB-to-RS232 adaptors I have seen (& purchased on eBay) seem to be all *defective*. This is a very late posting and perhaps this is not any issue anymore.
#QINHENG ELECTRONICS HL 340 USB SERIAL ADAPTER DRIVER DOWNLOAD ZIP#
1 download zip file of above adapter driver for Linux 2 extract it 3 run make command 4 connect USB serial adapter to raspberry pi ( I connected pin 2 and pin 3 of serial port together) 5 run putty on raspberry and select serial and type port as ttyUSB0 and clicked open 6 then new windows was popup and when i type on keyboard there is no any letters appear.Ĭursor position changed for some keys is it converter problem? Or is there any method to connect PLC with raspberry pi via modbus protocol? Geomax geo office crack key. The MCS7840 is an easy and cheap way to add 4,8,12. I presume the 2-port variant MCS7820 would also work seamlessly. They work straight off on current Raspbian 'stretch'.
The HL-340s gave about 0 to +3v.īut voltages are good from the PL2303 adaptors I have used. Cursor position changed for some keys is it converter problem? Or is there any method to connect PLC with raspberry pi via modbus protocol? This is a very late posting and perhaps this is not any issue anymore. 1 download zip file of above adapter driver for Linux 2 extract it 3 run make command 4 connect USB serial adapter to raspberry pi ( I connected pin 2 and pin 3 of serial port together) 5 run putty on raspberry and select serial and type port as ttyUSB0 and clicked open 6 then new windows was popup and when i type on keyboard there is no any letters appear. I need to use a USB to Serial adaptor but can't get the driver to load.
0 kommentar(er)
