Accessing device with Prolific USB-serial controller.

Applications Programming
1

I am trying to access DG-100 gps logger on Mac OS X with POSIX API. The device uses a Prolific usb-serial controller, and connect to the usb port on my mac.

After I install the Prolific driver, it shows up as /dev/tty.usbserial and /dev/cu.usbserial. The vendor has published the data format. So I write() the "get configuration" command to /dev/cu.usbserial, and get response back with read(). However the device doesn't seem to answer any command after the first one. I have to restart it to make it working again.

I am not sure if this is a general serial communication problem or specific to the device. When i talk to such a device, do I need to acknowledge in some way so that it will accept the next command?

Thanks.

2

Hi,

Maybe your device is blocking during sending output to first request.
I would try to use 'cat' to write and read in 2 different processes.
Run
cat > /dev/cu.usbserial
in one terminal and
cat /dev/cu.usbserial
in another.

Regards