I am designing a system to measure various signals. I am using at least 3 cRIOs 9074 to acquire data and to possibly control temperature processes. I am required to create one user interface for all the 3 cRIOs, even when they control different processes. In addition, I require to use a Yokogawa data acquisition system as an extension of the cRIO channels. This is what I am planning:
- Have the 3 cRIOs acquiring data at a high sampling frequency.
- Have the cRIOs send the data over the network using shared FIFO network variables.
- Have the user interface on a PC grabing that data from the 3 cRIOS over the network and present it to the user, allowing him to send commands over the network to the cRIOs via shared network variables.
-Have the PC running the user interface handle all the data logging and reporting.
- Program a cRIO to interface with the Yokogawa DAQ directly and have the cRIO send over the network the data, just as it did for the other data.
I would appreciate any thoughts on this matter.
Solved! Go to Solution.
This application sounds ok. I would highly recommend that you review the cRIO developers guide (especially Section 2 chapter 4 on cRIO Communication). It starts with shared variable communication, but then moves in to communication with TCP/IP.
Thank you for the answer. Any suggestion regarding the performance of the system?. Each cRio will have more than 100 thermocouple channels, plus 60 from the Yokogawa DAQ. Should I assume that using the FPGA module is mandatory (in lieu of the Scan Interface) in order to get acceptable sampling rates?
It depends on your sampling frequency. Usually with thermocouple samples you would sample relatively slowly, so you could use Scan Engine to take the samples since FPGA would be overkill. If you do need much higher sampling frequency, then you may want to use the FPGA. Here are some benchmarks for Scan Interface Mode.