using usb adapter with QJ71C24 card

[firefinder 0]

Maint dept ordered a torque tester to replace a bad unit. The old unit was rs232. The new replacement is usb. They tried to use a usb to serial adapter but it will not communicate. Is there any way to make this work with a QJ71C24-R2 card? I called Mitsubishi and they were not sure. Answer was probably not.

[kaare_t 155]

That depends on the USB side of the comm link. If the USB side can install the correct drivers for the USB<->Serial adapter then it will probably work. The RS232 side of the converter probably will support the C24 card since it is basically just a RS232 interface. What kind of unit is on the USB side of the comm?

[firefinder 0]

It is a CEDAR torque tester. You can not install drivers in the unit.

[firefinder 0]

Does someone make a stand alone adapter that can do this?

[kaare_t 155]

All USB devices natively needs a driver on the USB side.

[Crossbow 295]

It's not possible to connect a USB device to a QJ71C24. No PLC allows this. Your data logger is designed for use with a PC, not a PLC. You need to get one which is used for PLC communications.

[mohssen 0]

Hi Firefinder, Normally, a USB to RS-232 converter should work for your device. Because both USB and RS-232 are standard communication protocols and a standard converter should be able to convert the data package and physical medium without any problem. I think you should double check the COM port settings in your new card configuration. make sure that the USB-to-Serial COM Port is assigned correctly. There are many other settings that must be the same for the port and the device being communicated with. Typically the manual for the device being connected will outline the correct settings, like baudrate, parity, stop bits etc. I suggest you to try with another standard USB-to-Serial converter as well and see if you can communicate or not. for example you can use below converter which works properly with different products and modules: http://www.icpdas-usa.com/i_7560.html?r=mohsen The other issue which could be a reason for your communication problem, could be a special wiring for your serial device. you need to check its manual for pin assignment of its serial connector port. If so, you can use a converter with a terminal which allows you to wire your serial device directly to the converter terminal according your desire like below converter: http://www.icpdas-usa.com/i_7561.html?r=mohsen hope it works for you Good Luck :)

[kaare_t 155]

@mohssen: I completely disagree!! USB devices do not have a common driver or component like RS232. The easiest example is the built in Windows COM components for developing serial datatransfer applications. Windows and MS have a RS232 component library which can be used with any COM port resource like PCI, PCIe and so on. The COM port resource can even be used for USB devices, but only AFTER the driver for the USB device is installed. RS232 has a predefined standard that's common for absolutely ALL producers that makes use of the RS232 transreceivers, so it doesn't matter if it's a computer, PLC, "CEDAR", Arduino, or even your own homemade microcontroller. In essence, if you purchase an individual RS232 transreceiver you already have the predefined standard of communication, and the comm stack is fixed. USB devices all needs to have their drivers installed on the host system, that's why USB devices usually takes 15-45 seconds to "install" the first time, then takes at least 1 second to recognize the remaining times you plug it in (e.g. a USB Storage Device). The same goes for all USB devices. That's also why USB devices do not use physical IO resources on your host computer, it simply makes use of the serial attached bus (USB = Universal Serial Bus). And to take a small example from your manufacturer's website, and I quote part of the content in their site: "...I-7560 comes complete with drivers for Windows 98/ME/2000/XP/Vista/7/Linux..." That's exactly why you cannot connect the USB side of the USB device to a PLC or to a "CEDAR" unit like to topic starter is trying to. Unless the "CEDAR" unit is a full featured computer with ability to install USB drivers on it (Like Windows/Linux/MacOS) there's no chance this will work for him.

[Crossbow 295]

You can't install drivers for a USB device on a PLC, so you are not going to make this work. He is talking about connecting a USB device to an RS232 converter to go into a PLC. Not possible.

[mohssen 0]

Hi Kaare_t Thank you for your note. I admit you are right. I checked the converter and USB driver is required for PLC and it is difficult to install USB driver in a PLC.