Hello All, We've been experiencing some difficulties getting our two cRIO 9068s to communicate well with our other miscellaneous instruments, and it generally seems to be a problem on the Labview/Visa side of the equation. The project we're working on is related to using high temperature fuel cells for energy storage applications, and thus as you might imagine we have a relatively large number of instruments working on concert to both control and monitor the system. Quite a large percentage of our instruments still run some variation of serial communication and thus we've been working specifically on ways to easily network large numbers of serial devices into the cRIOs with easy expandability. Through a series of events we decided on using COTS usb hubs to break out the single USB port on the cRIO to connect to all of the miscellaneous devices with some sort of intermediate USB-Serial connection. This allows for easy expansion, inexpensive hardware, isolation between the devices and the cRIO, and relys on the linux kernel to handle all of the drivers. However, we've run into some problems getting everything to play nice, thus far the devices have fallen into three categories.1: FTDI Based chipset Devices: These devices (mostly homegrown equipment) work with very little effort. By adding the lines below to /etc/mdev.conf we are able to see the devices mount in linux ("lsusb"), load the appropiate drivers ("dmesg | grep tty"), and they immediately show up in NiMAX with their appropriate "ttyUSBn" port and Max reads Status: Present. ttyUSB[0-9]* root:tty 666 Note: The adding of this line to the mdev.conf was referenced by a number of different tutorials (1, 2 ) Creating symlinks was unneccesary in this case. These devices are immediately available for access using the standard VISA serial communication methods, and respond as expected. We've performed simple loop back tests, as well as actually communicated with devices and everything has worked. The "ftdi_sio" is noted here, as a driver known to work and so this result was expected. 2: Prolific based chipset devices: These devices (COTS USB-Serial converters) seem to load fine into the kernel, the driver PL2303 is loaded, a new ttyUSBn shows up, and they also pop up in Ni-MAX. Again, no symlink is needed to make Visa realize a new interface is available, however, the Status in Max reads as "Not Present." Attempting to run a loop back test using the Simple Serial.VI results in this error: "Error -1073807360 occurred at Property Node (arg 1) in VISA Configure Serial Port." Attempting to remove the driver using "rmmod pl2303" has the desired effect o removing it from linux (as noted here) but also removes it from VISA. These devices do not seem to work though the driver is noted as supported here. 3: Atmel based USB to Serial Chipsets. These devices (things like Arduino Unos) are loaded into the kernal as "USB Modem Modules," using the driver cdc-acm providing the line below is entered into /etc/mdev.conf. They register as ttyACMn, as expected, and do not show up in Visa. Creating a Symlink to something like ttySn does allow them to show up in VISA however, they also register as "Status: not present" in Max and they fail the Simple Serial.VI with this error: Error -1073807360 occurred at Property Node (arg 1) in VISA Configure Serial Port. However, these devices are publishing data regularly over serial and by using "cat < /dev/ttyACMn" we can read the serial output of the device. ttyACM[0-9]* root:tty 666 Furthermore it is possible to remove the cdc-acm driver from the kernal (rmmod cdc-acm), and this causes the devices to show up as raw USB devices but this doesn't seem to enable any useful communication.. Any ideas guys? We're planning on building all of our new hardware to only use FTDI chips, but it'd be nice to use the stuff we currently have. And particularly since it seems like the kernel doens't have any problems running these devices it'd be nice to figure out how to get LabView to place nice. Cheers ~ MicahSystem: cRIO-9068Firmware: 1.0.1f0OS: NI Linux Real-Time ARMv7-A 3.2.35-rt52-1.0.0f1NI-RIO V: 13.1NI-VISA: 5.4.1Labview RT 13.0.1Labview 2013

NI Linux Real-Time Discussions

Hello,

I already make changes and I can not activate the com port.

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