02-11-2019 04:10 PM
Hi All,
I have a cDAQ-9135 device which has one RS-232 port that can communicate at a max baud rate of 115 kps.
I need to receive serial data from one device at a baud rate of 9600 bps and transmit that data (concatenated with other data) to a different device at 100 kps. Can I do this with one serial port by connecting the output of the transmitting device to the RX pin and the input of the receiving device to the TX pin? I feel like the difference in baud rates requires two different ports, but I would then have to switch over to a cRIO chassis since the serial port module (NI-9870) are not compatible with the cDAQ chassis.
Any nuggets of wisdom or help would be greatly appreciated.
Thank you.
Solved! Go to Solution.
02-11-2019 05:56 PM
Assuming you need to process all of the data, the 2 baud rates means you need 2 ports. May you can change the settings of one device to match the other?
02-12-2019 02:02 AM
Easiest solution would be to add a USB to serial adaptor. Should be easy assuming the cDAQ runs windows, maybe you need to check compatibility with LinuxRT if you're using that.
0xDEAD
02-12-2019 02:50 AM
@deceased wrote:
Easiest solution would be to add a USB to serial adaptor. Should be easy assuming the cDAQ runs windows, maybe you need to check compatibility with LinuxRT if you're using that.
Or a (Moxa or NI) TCP\IP to Serial converter. That's supported for sure.
Under Windows these devices add 4\8\16 serial ports, if you install the drivers. But if you don't (or can't, on a RT system), you can directly send data to the serial ports over TCP\IP.
As long as you didn't use bytes at port (which is mostly evil anyway), usually changing the VISA resource from serial to TCP\IP address and port is sufficient to get it working, after setting up the Moxa.
02-12-2019 05:01 AM
Arduino Mega (having 4 UARTs) and a few MAX233 chips would also be a nice easy cheap solution
02-19-2019 08:29 AM
After discussing with an NI Applications Engineer, we determined that the cDAQ-9135 can receive serial data at 9600 bps into the RS-232 port on the chassis and it can output serial data from the USB port at a rate of 115kps. With a USB to DB-15 connector cable, our system is complete.