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This is something I had to design for our company's test benches because nothing existed off-the-shelf. (What does exist off-the-shelf is beyond incredibly expensive.) It's a card chassis holding 4 cards with 8 individual (5 amp) relay channels per card. Each relay channel has eight selectable sources or sinks. In our case, we have V+ (from a programmable bench power supply), ground, 4 individual resistive dummy loads each with analog DAQ channel, digital input, and an external header connector. There are four programmable 50 watt resistive dummy loads ranging from 1 ohm to 255 ohms. There are also two analog output channels. All of the switches, power supply, and dummy loads are controlled from a PC serial port (I would use USB now, if I had a chance to re-design it.) The inputs are all fed to a PCI-6221 and a PCI-6514. Again, if I had a chance to re-design it, I would ditch the PCI cards and use an FPGA with several A/D converters and digital opto-isolators. I would also consider getting rid of the mechanical relays and try solid-state relays, although we have not had a relay failure in any of the 292 relays (per chassis) in over ten years of daily use.

Something like that, only more widely expandable would be very useful to anyone testing a wide range of devices with different signal connections and high output currents. I would design these myself to sell, if I were more ambitious.

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VirtualBench App Improvement for MSO

Hi Idea Exchange team,

VirtualBench App looks great since last update, by the way it could be great to add features like boxed scopes have, like :

Channel scale customization : actually, we can only use the "10x", could be nice to be able to use also a custom scaling (equation and unit)
Native phase shift measurement : actually we can use cursors to retrieve this data, but will be great if directly displayed
Update mode : could be also great to switch between Strip, Scope and Sweep mode like in LabVIEW waveform chart

Any suggestion welcome !

Mathieu,

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cDAQ Chassis with integrated PoE/PoE+

Having the ability to connected a cDAQ chassis to a PoE or PoE+ switch.

Then the cDAQ does not have to be powered locally.

Ethernet is throughout our facility the ability to drop a cDAQ chassis with sensors and not worrying about power would be helpful.

Currently I am using external hardware to power cDAQ chassis off of PoE+ switch, it would be nice if it was integrated.

One of my nodes includes 4-slot chassis with two CAN cards, a temperature card and an accelerator card.

The term "Incomplete Sample Detection" comes from DAQmx Help. It affects buffered time measurement tasks on X-series boards, the 661x counter/timers, and many 91xx series cDAQ chassis. It is meant to be a feature, but it can also be a real obstacle.

How the feature works ideally: Suppose you want to configure a counter task to measure buffered periods of a 1-channel encoder. You use implicit timing because the signal being measured *is* the sample clock. The 1st "sample clock" occurs on the 1st encoder edge after task start, but the time period it measures won't represent a complete encoder interval. Reporting this 1st sample could be misleading as it measures the arbitrary time from the software call to start the task until the next encoder edge.

On newer hardware with the "Incomplete Sample Detection" feature, this meaningless 1st sample is discarded by DAQmx. On older hardware, this 1st sample was returned to the app, and it was up to the app programmer to deal with it.

Problem 1: Now suppose I'm also using this same encoder signal as an external sample clock for an AI task that I want to sync with my period measurement task. Since DAQmx is going to discard the counter sample that came from the 1st edge, my first 5 samples will correspond to edges 2-6. Over on the AI task, my first 5 samples will correspond to edges 1-5.

My efforts to sync my tasks are now thwarted because their data streams start out misaligned. The problem and workaround I'm left with are at least as troublesome as the one that was "solved" by this feature.

Problem 2: Suppose I had a system where my period measurement task also had an arm-start trigger, and I depended on a cumulative sum of periods to be my master time for the entire system. In this case, the 1st sample is the time from the arm-start trigger to the 1st encoder edge, and it is *entirely* meaningful. On newer hardware, DAQmx will discard it and I'll have *no way* to know my timing relative to this trigger.

Older boards (M-series, 660x counter/timers) could handle this situation just fine. On newer boards, I'm stuck with a much bigger problem than the one that the feature was meant to solve.

So can we please have a DAQmx property that allows us to turn this "feature" OFF? I understand that it'd have to be ON by default so as not to break existing code.

-Kevin P

The NI-9203 noise probelem is discussed in http://forums.ni.com/t5/Multifunction-DAQ/NI-9203-generates-noise-pulses-when-acquired/m-p/3546439

Attached document describes how noise measurements were perfromed with oscilloscope. 9203 emits peaks with the same frequency as acquisition rate. These spikes do affect 4-20mA measurents accuracy quite a bit. It should not be like that. Probably 20pF capacitance on each input inside the module shoud be increased to 200pF or 2nF. I am sure that NI R&D knows better how to improve 9203 🙂

Support reference#: 2703970

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Modern Upgrade for ExpressCard-8360

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DMM for low resistance

Hi all,

Biomedical applications have become more popular. Specially in bioimpedance field (see link for more information), where usually the equipment used for this is quite expensive... so researchers and students with low budget usually stick to a custom design systems.

Currently, I am using a Red Pitaya board which has these 2 fast analog outputs and 2 fast analog inputs up to 125MHz sampling frequency to develop my own. This board uses the same processor and fpga as myRIO. However, sampling frequency's myRIO is 500ks/s much lower than Red Pitaya.

My idea would be to develop further hardware to have at least these 2 fast analoge input and 2 fast analog output to be able to compete with Red Pitaya board. I believe that having these characteristics into myRIO will be greatful for those researchers who dont have either the money or the knowledge to put together a system capable of doing that.

Cheers,

Albert

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scsi cable to USB

High Bandwidth Counter Device

The 6602 can take an external timebase up to 80 MHz (according to the spec, it's actually a bit higher than this in reality).

The newer counter products do not have this capability (e.g. the 6612 has the same 25 MHz bandwidth limit as most of the multifunction products).

So whenever an application comes up (e.g.) where the user wants to count a fast external signal, the only reasonable option from NI is the 6602. This is fine for now, but in the future it would be nice to have some higher bandwidth counter options (unless you plan on selling the 6602 forever... hopefully it doesn't get too hard to come across computers with spare PCI slots though).

Every n encoder pulses callback

It is a frequent requirement to make measurements on production lines. Position on these is often tracked with Rotary Encoders https://en.wikipedia.org/wiki/Rotary_encoder . Many NI devices can accept the quadrature pulse train from such a device, and correctly produce a current position count. The information in the 2 phase pulse train allows the counter to correctly track foward and reverse motion.

What would be very useful would be a callback in NI-DaqMX that is called after every n pulses, ideally with a flag to indicate whether the counter is higher or lower than the previous value, i.e. the direction.

This has recently been discussed on the multifunction DAQ board here: http://forums.ni.com/t5/Multifunction-DAQ/quadrature-encoder-based-triggering/td-p/3125468 . So I am not alone in requesting something more programmer friendly than the workaround offered there.

The vast majority of my working life is spent with RIO devices or midrange X series cards, but I often come across applications where an inexpensive, reliable DAQ would be handy for low level tasks - monitoring presence sensors, measuring voltages at moderate precision and slow speed, providing interlocks for material storage bins etc.

Traditionally, you'll see a lot of USB 600X units being used for applications like these. However, running on USB has a few associated problems: unreliability of the Windows bus, cable strain relief on USB connectors, mounting of USB 600X units, connection type. Don't get me wrong, you can do a lot with these units but they're not an ideal, inexpensive solution for production processes.

There's a jump between the functionality of these USB units and X (or even M or E for the vintage crowd) series cards. The only thing that's really in that range anymore is the B series PCI-6010 card, which has the fantastic benefit of using a 37W DSUB connector too, but is a little limited in terms of channel offerings and the like.

I'd like to see the B series range revived to provide products that fit between the PCIe-6320 and the USB 600X devices, providing non-USB connection and preferably with a DSUB backplane connector for cost and ease of use. This would provide a more reliable offering for simple acquisition tasks in the industrial environment at a cost-effective price point.

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We mostly develop PXIe based high speed (RF) applictions which stores data on one or more RAIDs.

Several customers already asked for a high speed ethernet connection do move this data over the net.

Yet there is only one PXIe 10 GBE availible and it is NOT from NI.

We would already need a 40 GBE solution the comming year.

PCI Express 40 GBE ist almost commonly avalilible, a mezzanine board solution would be sufficient if nothing else works.

But there is no carrier board availibe, too.

I feel kind of left alone with all this data, waiting on those bigg RAIDs for beeing processed / copied.

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Currently with a multislot chassis, the system will operate at the requested sampling rate even if that rate is above the maximum supported by the module. In this case, the chassis will replicate the additional required data points from the previous sample, and will not return an error in NI MAX. With a single slot chassis, this is not an option. However, it would be helpful if this feature was also supported with the single slot chassis so that data could be replicated at a higher sample rate without returning an error message.

Relevant KnowledgeBase article: Why is My Slow Sampled C Series Module Able to Operate at a Higher Sampling Rate than the Specified Maximum Rate?

Currently there are only two options for acquiring +/-60V input signals:

NI 9221: 8-Channel, ±60V, 12-Bit Analog Input Modules ($582)

NI 9229: 4-Channel, ±60 V, 24-Bit Simultaneous,Channel-to-Channel Isolated Analog Input Modules ($1427)

I would like to see a new module provided that is identical to the NI9205 (32-Channel Single-Ended, 16-Channel Differential, ±200 mV to ±10 V, 16-Bit Analog Input Module, $881) but with an input signal range of ±60 V.

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I use a PXIe-6363 which a wonderful device. But it lacks level shifting at the digital I/O.

I would recommend that most DAQ multi-io devices support programmable and externally driven level-shifting for digital IOs. Range for DAC driven level-shift (0.8 - 3.6, 5V), and support for external input. It would also be nice if multiple ports are present that some of them allow independent logic levels. Default level should be 3.3V. Port configurable pull-up, pull-down and latch-hold.

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Data Acquisition Idea Exchange

Hardware idea: High current switching matrix and multi-channel dummy loads

VirtualBench App Improvement for MSO

cDAQ Chassis with integrated PoE/PoE+

Allow "Incomplete Sample Detection" to be disabled for counters

DAQXmx conditional logging (Triggered logging)

Improve (decrease!) noise generation emitted by NI-9203 to the inputs

Modern Upgrade for ExpressCard-8360

Additional option for Virtualbench I2C address decoding for 8 digits

DMM for low resistance

To have at least two fast analog outputs and two analog inputs up to 125MSamples/s

scsi cable to USB

High Bandwidth Counter Device

Every n encoder pulses callback

Low cost PCI-based alternative to UBS 600X series units

Fast ethernet (10 / 40 GBE) for high speed applications

Add the ability to replicate data from a slow-sampled device to single slot DAQ chassis

Create a new ±60 V version of the NI9205 C-Series Module

cRIO support hardware module for LVDT input

Hotswap laptop connection to PXI (currently using 8360)

DAQ Hardware Digital I/O - Some cards only do TTL 5V and it would be nice to have level shifting (programmable or externally driven)