We really need a hard drive crio module for long term monitoring and reliably storing large amounts of data remotely.
1. Solid State Drive: Fast, reliable, and durable. Extremely high
data rates. It would be a very high price module but it could be made to
handle extreme temperatures and harsh conditions. It should be
available in different capacities, varying in price.
2. Conventional Hard Drive: This would give any user the ability to
store large amounts of storage, in the order of hundreds of Gigabytes.
This type should also come in varying storage capacities.
For this to be useable:
1. It would need to support a file system other than FATxx. The risk of data corruption due to power loss/cycling during recording makes anything that uses this file system completely unreliable and utterly useless for long term monitoring. You can record for two months straight and then something goes wrong and you have nothing but a dead usb drive. So any other file system that is not so susceptible to corruption/damage due to power loss would be fine, reliance, NTFS, etc.
2. You should be able to plug in multiple modules and RAID them together for redundancy. This would insure data security and increase the usability of the cRIO for long term remote monitoring in almost any situation.
Current cRIO storage issues:
We use NI products primarily in our lab and LabVIEW is awesome. I hope that while being very forward about our issues, we will not upset anyone or turn anyone away from any NI products. However, attempting to use a cRIO device for long term remote monitoring has brought current storage shortfalls to the forefront and data loss has cost us dearly. These new hard drive modules would solve all the shortfalls of the current storage solutions for the crio. The biggest limitation of the cRIO for long term monitoring at the moment is the fact that it does not support a reliable file system on any external storage. The SD Card module has extremely fast data transfer rates but if power is lost while the SD card is mounted, not only is all the data lost, but the card needs to be physically removed from the device and reformatted with a PC. Even with the best UPS, this module is not suitable for long term monitoring. USB drives have a much slower data transfer rate and are susceptible to the same corruption due to power loss.
When we have brought up these issues in the past, the solution offered is to set up a reliable power backup system. It seems that those suggesting this have never tried to use the device with a large application in a situation where they have no physical access to the device, like 500 miles away. Unfortunately, the crio is susceptible to freezing or hanging up and becoming completely unresponsive over the network to a point that it can not be rebooted over the network at all. (Yes even with the setting about halting all processes if TCP becomes unresponsive). We would have to send someone all the way out to the device to hit the reset button or cycle power. Programs freeze, OS' freeze or crash, drivers crash, stuff happens. This should not put the data being stored at risk.
I would put money on something like this being already developed by NI. I hope you guys think the module is a good idea, even if you don't agree with all the problems I brought up. I searched around for an idea like this and my apologies if this is a re-post.
The possibility to use simulated devices, so that you can design software without having the hardware available is very nice. Sometimes, specific signal profiles are needed. It can be tested using additional software, but you really have to change the software (add test-software in the code). In some cases this is not wanted.
Therefore adding in DAQmx a possibility to force specific output can be very helpful. Different possibilities exist (TDMS-files, LlabVIEW(/compiled LabVIEW)-code, ...). Different people will want different possibilities, but some extra possibilities are useful.
When using TEDS load cells it would be useful to have a built in tare function The null offset function only offsets the electrical value by the intialy measured amount. This essentially shifts the calibration curve horizontally only. The tare function could also shift the calibration curve vertically, in the load direction. Since two point calibrations don't always create a line that goes through zero, a tare function is needed to get to zero. Please see the attached VIs. Also, check out my thread on this subject.