Load Cell Input UMI 7764

Hi. I have a UMI 7764 and I want to use it control a stepper motor and load cell input. I am using a power supply connected to the analog input on the card to simulate a load cell. However I can not find/read it in MAX. I am able to control my stepper motor with no problems.
Any input would be appreciated! Thanks.

Hi Kenny,
First off, you may notice that this forum thread is nearly 6 years old. In the future, you'll typically have better luck getting responses by posting to a new thread on the motion forum.
To answer your questions:
1. The analog inputs on the NI 73xx motion controllers are not capable of being hardware timed, and therefore are limited to very slow sampling rates. This KB explains more. You'll notice that AI sampling rates are slower when used with onboard programs since the onboard controller must share processor time with higher priority tasks.
2. You can find more info about using onboard programs with 73xx motion controllers here. Also, there are a lot of shipping examples that show how to use the NI-Motion API and onboard programs. You can find all of those under Hardware Input and Output>>Motion Control>> NI 73xx in the Example Finder.
Cody A.

Similar Messages

What are the 4 analog inputs of my umi-7764 (on the analog input terminal block)

I would like to known what are and how connect the 4 analog inputs of the anolog input terminal block of my umi-7764. I am french, so if you want to answer in french, it will be easier for me .

Sébastien,
Selon la carte de contrôle d'axe que vous utilisez (7344, 7334 ou autre), vous pouvez disposer d'entrées analogique.
Si votre carte possède des lignes analogiques (voir la documentation de celle ci), cela signifie que vous pouvez les utiliser pour 2 choses:
1. Utiliser ces lignes analogiques pour le feedback (retour en position) de vos servo moteurs. Cela veut que vous travaillez avec un servo, et que vous êtes en boucle fermé. (Pour informations, un servomoteur peut aussi asservi avec un retour en position).
2. Si vous ne faites pas d'asservissement en tension ou que vous controliez un moteur pas à pas, alors ces lignes d'entrée analogique, peuvent être utilisées comme des lignes classiques. Pour les utilisez dans ce cas, vous devez cabler
votre signal sur l'UMI (qui n'est qu'une interface entre vos signaux et la carte) de la manière suivante:
- Le point chaud du signal sur "Analog Input X"
- Le point froid du signal sur "Analog Inout Ground"
De plus si votre carte de contrôle d'axe intègre des entrées analogiques, vous pouvez configurer leur gamme dans MAX (Measurement & Automation Explorer) le range de ces voies (+/-10, +/-5, 0-5 et 0-10 V).
(Comme l'UMI est un bloc générique, assurez vous bien que votre carte possède des entrées analogiques)
Finalement, pour lire le niveau de tension sur ces entrées, il existe dans le driver NI-MOTION, la fonction "Read ADC".
sur http://www.ni.com/manuals
vous trouverez la documentation de votre matériel.
A l'adresse ci dessous, vous trouverez de l'aide concernant la configuration de votre system motion dans max:
http://zone.ni.com/devzone/conceptd.nsf/webmain/081957EE013C7A4586256B92007818E0?opendocument
Raphael TILLET
Ingénieu
r Application
NI FRANCE
Cordialement,
Raphael T

Is possible to give a 5V input to the umi 7764 connector blick for the limit switch inputs

I am using a umi7764 connector block for my 7344 controller. My motion control hardware provides me a 5V output in case the limit switches are enabled. But the umi 7764 connector block connections for the limit swithces are in such a way that it doesnt get any input, instead it has to be directly connected to the limit switches.Is there any way to come around this problem so that the limit switch inputs read the 5v given out by my motion control appplcation

If your drive has individual outputs for the forward, reverse, and home switches, then you could connect these to the their respective terminals on the UMI. You will need to either disable limit functionality on one component (controller or drive) or make sure the limit behavior for the devices does not conflict with each other. It probably is best if the controller handles the limits, but this will depend on your application.
If the drive only has one output to indicate that one of the switches has been activated, then you have fewer options. In this case, you should probably just use the limit protection on the drive and poll that single output with another input on the UMI.
Regards,
Brent R.
Applications Engineer
National Instruments

Using a CW230 Bi-polar driver with the UMI-7764 and 7330 PCI. But clock level is loaded below 2v and motor will not run?

I have my stepper driver connected to the +step and aogrnd terminals on the UMI-7764. With the driver connected to these terminals the output across the two is 2vp. When I disconnect the driver, the level returns to a 5vp signal. My drivers inputs are optically isolated so I suspect the impedance my be higher than TTL can drive. Is there any way to manually set the output parameters of the 7330 Motion controller?
Thx...Vic

Hi Vic,
Take a look at this KnowledgeBase: How Do I get the 73xx Controller and UMI-7764 to Drive a Third Party Stepper Motor?
I think it may have the solution to your problem. Also, here is another KnowledgeBase that is relavent:
Why Do I have to Supply Power to my UMI-7764?
I don't believe there is a way to manually set the output parameters of the 7330, but I don't think this is the source of the problem. If the KnowledgeBase articles are not the solution, post back and we'll keep troubleshooting!
Kristen H.

Controlling Linear Actuator via Load Cell

Hello,
I need to control the position of a linear actuator based on the force feedback from a load cell (rated up to 100 ft/lbs) connected to the tip of the linear actuator. What I want to be able to do is to set a force and have the linear actuator (driven by a stepper motor) move until it is within 0.1 ft/lb of the force setpoint. Once within 0.1 ft/lb of the setpoint, I would like to hold and control to the setpoint based on a user configured hold time.
I have the following hardware:
PXI-1033 chassis
PXI-7340 Motion controller card
UMI-7764 Terminal Block
P7000 Drive
Omega Engineering Load Cell model number LC201-100
Omega CCT-80 Load Cell Signal Conditioner
Omega FAR-1 Power Supply
I have the + output of the CCT-80 connected to the Analog Input (AIN1) and the - output connected to the Analog Input Ground (AIGND). This output signal is -10V to +10V (verified by DMM)
I have the ADC range set to -10 to +10
I'm reading the ADC as fast as possible (get about 700 samples/second) and this just isn't fast enough to control to the precision that I need. Also, it seems like there is a substantial amount of noise on this line.
Does anyone have any recommendations on improving the speed of the ADC read, or how to reduce the noise on the line?
If my requirement of holding to 0.1ft/lb is too strict for this hardware (7340 motion card) is there something else that I should try?
If I'm missing any other info that is needed to help me out, let me know and I'll update this post.
Thanks!

Hello AMac,
I have a setup similar to yours with a load cell attached to a linear stage. I want to use position control of the stage to apply a set load on the load cell (position-based explicit force control). Do you have a example VI I could look at if yours was successful?
Thanks,
Kyle

Is it possible to condition a load cell signal with a 1520 SCXI and then use it as the primary analog feedback for a 735X motion control board?

My system
PXI 1052 chassis
PXI 8196 RT controller
Flexmotion 7356 motion controller
Flexmotion 7354 motion controller
6259 M series DAQ
1520 SCXI
1520 SCXI
1314 SCXI frount mounting terminal block
DSM strain gage load cells
Exlar SR Brushless PM motors
Kollmorgen servo star CD series 5 drives
My objective:
I want to measure the force on the load cells with the 1520 SCXI (i.e. excite the load cell then amplify and condition its output) then I want to use this analog (force) signal as the primary feedback for my motion control system (7356 and 7354 motion controller connected to my drives and motors).
The problem:
The motion controller boards (7356 and 7354) can be configured for force feedback control via analog feedback from a load cell. However the boards implicitly expect the load cell signal to be amplified and conditioned with and external signal conditioner rather then using an NI SCXI module. Currently I’m am reading the SCXI signals via the 6259 M seriers DAQ and consequentially have no way to route the signal into the 735X boards for force feedback control. I can use softmotion to control the motors but then I loose the fast PID update rates possible with the 735X boards.
The question:
Is it possible to condition a load cell signal with a 1520 SCXI and then use it as the primary analog feedback for a 735X motion control board?
Thanks
Patrick Aubin
Ph.D Candidate
University of Washington &
VA MedicalCenter of Excellence for
Limb Loss Prevention and Prosthetic Engineering

Hi GG,
Thank you for your feedback.
>create your own external circuitry to amplify the signal.>
True a few op-amps could amplify and filter the signal externally but the performance of such an amateur built system will never match the accuracy and functionality of the 1520 SCXI. That’s why we spent the $2500 for the professional version.
>One thing that you could do is to use a UMI with your motion controller and then wire your signal from your SCXI to the UMI.>
As I understand it the UMI is basically a break out connectivity interface for third party drives. After conditioning and amplifying the analog force signal with the SCXI module the analog signal isn’t available to wire into a UMI. To my knowledge the conditioned signal of the SCXI resides only in the PXI backplane (i.e. there is no physical access to the conditioned analog signal). Can you explain how the UMI could be help here.
Again thanks for your input GG.
Patrick

Dynamic force control using linear servo actuator + load cell

Hello,
I am designing a test fixture which will allow us to test the performance of actuators we install in our products. I need to apply a constant load to the actuator while it is extending/retracting. I would like to be able to use a linear servo actuator and a load cell on the same axis as the UUT to provide and monitor the load. The actuator under test does not travel at high speeds, its max speed is approximately 1in./sec.
I need to be able to maintain a constant load while the actuator is moving. Therefore I'll need some kind of closed loop system to maintain a velocity such that the load being reported from the load cell is equal to the expected load as the actuator is moving.
I am trying to figure out how to best implement this in a cost effective and time-saving way. I have not purchased any hardware at the moment so am open to suggestions. We do have LabView 2009 with all the toolkits. Would it be best to implement this using a motion controller card or would I be able to get good results using a standard DAQ?
Message Edited by fnaeem on 02-05-2010 05:58 PM

As you have stated correctly, you will need a deterministic closed loop system to accomplish this task. The most cost efficient while reliable solution for this purpose is a motion control board like the PCI-7352. This board provides quadrature encoder inputs for positioning tasks and analog inputs for any other type of control. Torque/force control is a very typical task for this board and it provides a simple API and useful configuration tools.
If cost savings are a primary goal, you could also use a PCI-7342, but for your application I would recommend the PCI-7352, as the PCI-7342 provides only 12-bit ADCs, while the PCI-7352 provides 16-bit ADCs, resulting in a much better resolution of your force feedback signal.
I hope that helps,
Jochen Klier
National Instruments

Data acquisition from a 250N Load cell

Hi ,
I am very new at using the Labview.I am using Labview 6i(PCI 6052E).The load cell(250N) is connected to a pump.The pump has 2 bags.One of them is filled with water and the other is empty.I want to load the bag which is empty from the bag filled with water using the pump.The load cell is connected to the bag which is filled with water.I am trying to aquire a volatge signal continously from a load cell and display it on a chart.
My program has no errors and I am able to run the progam.But it is not aquiring any signal.Could u please help me out.Attached is my code for the same .
-Manasa

Hi Manasa,
Make sure you are handling your errors in your code. You can do this by wiring your error clusters through your VI and then terminate them in a General Error Handler VI. If you are doing this, make sure that your device works in Measurement & Automation Explorer (MAX). Do this by opening a test panel and verifying that you can get a known voltage (like a battery) to read correctly. If you can successfully get a voltage in MAX, try running one of the example programs. You can find them at Help » Find Examples..., then browse to hardware input and output. If you can get an example program that is similar to what you are trying to do to work, try comparing your code to the example.
Please post back if you have any questions. Have a great weekend!
Ryan D.
District Sales Manager for Boston & Northern New England
National Instruments

Data acquisition from switching 500lbs load cell to 100lbs load cell

I am using 500lbs load cell, and acquiring data by inputing 2volts from 2345 signal conditioning board, and sensor output is connected to SCC-AI03 pin 3 and 4 , and configure this load cell to a channel using NI MAX, data neighborhood, traditional NI-DAQ virtual channel, the physical quantity is voltage set at range -10 to 10, and sensor also set at voltage with no scaling, but, I couldn't get any signal when 100lbs load cell is use, the difference of this 100 lbs load cell is the rated output is at 2.958mV/V, while the 500lbs rated at 1.8295mV/V , how should I do this?
Thanks.

Hi,
At this point, it is difficult to determine exactly what is happening to your acquisition. Could you please provide some additional information by answering the following questions:
What voltage are you reading with the 500 lb load cell?
Would it be possible to connect your load cells to a DMM and see what voltage reading you receive? If so, what do you see?
What is specifically happening when you connect the 100 lb load cell?
I also noticed that you are using the Traditional NI-DAQ (Legacy) driver. I recommend upgrading to the NI-DAQmx driver. Here are a couple of links with more information about DAQmx:
Advantages of NI-DAQmx:
Transition from Traditional NI-DAQ to NI-DAQmx:
Learn 10 Functions in NI-DAQmx and Solve 80% of Data Acquisition Applications:
Regards,
Hal L.

Not getting accurate readings off a calibrated load cell

I'm using a Cooper Instruments 200 lb load cell connected to a SCB-68 connector box hooked up to a 6036e DAQ card, and I'm having trouble calibrating it. (I've done this before, but it's been a while, and something just isn't working right.) So, I'm using the calibration wizard (the channels are set as Custom Voltage with Excitation), hanging a bunch of known weights from the cell, entering the values, and all that is going fine. However, when I go to use the load cells (in a very simple VI that just reads the value from the cell), it's reading consistently low by 2-3 pounds. I'm using a 10 V excitation signal, and I set the low end of the Signal Input Range to 0 (it kept wanting to set -5=-5 in the calibration when the low end was -5V, and that was even worse). I've tried modifying a custom scale, and that isn't fixing the problem either. Has anyone encountered this before or have any ideas on what else we can try?
Thanks,
Eric Martell

Hi Eric,
This is a curious problem. Is it every point that has a constant offset or does the offset vary from point to point?
Also what is the model number and sensitivity of your load cell? Have you gotten it to read correctly before? You mentioned that the values were stable out to the fourth decimal place, but haw significant is this decimal place? For instance, when I open the calibration wizard, the values can jump around depending on what I am measuring. If you load cell has a sensitivity of 1 mV/lb, then this could be large variations depending on what the decimal point was when you saved the value.
With regards to my mentioning averaging, when you first click the calibrate button in the DAQ Assistant, the first screen has a Number of Samples to Average control and a Rate control. If you leave the # of samples to average at 1000, but change the rate to 10,000, do the values begin to vary?
Regards, Mallori M.
Mallori M
National Instruments
Global Customer Education Program Mananger
Calculate the time you will save with NI Training

How to send an analog output signal on same axis running a stepping motor umi 7764/ PCI7334

I am running a single axis stepping motor (which is working fine) but
for the application I need to be able to turn on and off a 5 volt
laser. It notes in the manual for the UMI 7764 that the the
analog output can be used as a general-purpose voltage output. I
would like to use it as such, but can't figure out what VI's actually
send messages to the board to output a 5 Volt signal.
Ideally I would use the analog output on the same axis that the
stepping motor is on, but if need be I could use one of the other axis
if this isn't possible (ie. it may not be possible to step and send
analog voltage output on same axis at same time). I have been
looking at the configuring DAQ and ADC stuff, but can't seem to make
sense if these actually control the analog output channel. I
think they just control the Analog input channels, but maybe I am
wrong.
Any help would be greatly appreciated
Andre

Hi,
It is possible to send analog output out of the same same DAC channel in which your stepper is connected, if you configure the stepper as open loop in MAX. I've tried it. This way you have the stepper output, analog output and encoder input acting independently. So you can use these seperately for different purposes, such as using the analog output for constant speed motors where speed or position control is not of much importance, encoder for positioning some other axes and stepper output for stepper control. With good programming skills, the NI motion controllers can thus be used for the most complex configurations. Great work NI !!! Nothing is impossible.
Regards,
Giridhar Rajan
Automation Engineer, Design
Cruiser Controls
Mumbai, India

UMI 7764 second axis not working

I have a strange problem with my NI motion control setup and I wondered if anyone could help me.
I have the following setup:
PCI-7330 connected to a UMI-7764
Connected to the UMI-7764 I have two P70530 stepper drives, themselves connected to two Nema-23 stepper motors with shaft encoders wired back to the UMI-7764. All following the manual.
The 'Inhibit Input' switch is set to active high and the 'Inhibit output' switch is set to active low.
Both P70530 drives initialise (solid green LED). The stepper drive and motor connected via the 'Axis 1' terminals of the UMI-7764 works fine. The second one, connected via the 'Axis 2' terminals does not. When I attempt to start a motion via MAX, the motor audibly "clicks" once and then disengages. The drive then has a flashing green LED.
The motor will remain disengaged until I attempt a motion in the opposite direction, at which point the same "click" is heard and the motor is now engaged. No motion other than the vibration caused by the motor engaging/disengaging occurs.
Both drives and encoders are wired identically into the UMI. I have switched the cables with the drive that works, as well as the drives themselves and even the motors. The result is always the same; the drive/motor wired to 'Axis 1' works fine and 'Axis 2' "clicks" but doesn't move.
I'd appreciate any advice or suggestions anyone can provide, please.

A bit more information in case anyone can help me:
Repeating the attempted motions in MAX for each axis I probed the poles of the UMI connected to the stepper drive. The results are below.
The Inhibit Input of Axis 2 seems to be always at 5V.
The 'Inhibit Input' switch on the UMI is set to active high and the 'Inhibit output' switch is set to active low. I would have expected, therefore, that reversing these switches would make Axis 1 stop working and Axis 2 start working. However, when I did this Axis 1 stopped working but Axis 2 continued the same behaviour (i.e. any attempted motion causes the motor to "click" and then disengage).
I also attempted to reverse the Inhibit Input action via MAX, but the option is greyed out.
Is there any reason why Axis 2 would be forced into having Inhibit Input at 5V? And, more to the point, is there a setting to stop it happening, or is this a hardware failure?

How can I connect GV-U6E to UMI-7764?

We have Compumotor GV-U6E (gemini servo drive), PCI-7344 & UMI-7764 for third party amplifier to operate Linear Servo Table. Some connections is not clear to understand. I will appreciate it if anyone can helo us connect the pins. The pin connection (GV-U6E) is attached.
Attachments:
GVU6E.pdf ‏44 KB

Most of pin connectors are wired, but I am not sure of them.
So now I am giving you the pin maps referring to Gemini GV hardware installation guide (Input and Outputs, page 60), 406 LXR Series manual (3.43 Limit and Home Connections, page 14), and UMI-7764 Manual (page 5).
Motor & Drive Pin connector -----> PCI-7344 (National Instrument) motion controller
Positive Limit (Orange, Limit & Home Cable) -----> Forward Limit
Home (Green, Limit & Home Cable) -----> Home Input
Negative Limit (Blue, Limit & Home Cable) ------> Reverse Limit
43 (Output 2 Drive Flt, Drive Connector) ------> Inhibit Input
24 (+- 10V Cmd-) ------> Digital Ground
23 (+- 10V Cmd+)
------> Analog Output
25 (Analog Ground) ------> Analog Ouput Ground
2 (Digital Ground) ------> Inhibit Output
+5 to +24VDC (Red, Limit & Home Cable) ------> +5V (Output)
Yellow, Black(Ground), and 1 (Enable) -------> Digital Ground
14 (Encoder Out A+) --------> Encoder Phase A
15 (Encoder Out A-) --------> Encoder Phase A bar
16 (Encoder Out B+) --------> Encoder Phase B
17 (Encoder Out B-) --------> Encoder Phase B bar
12 (ZX+ ) --------> Encoder Index
13 (ZX-) ---------> Encoder Index bar
For the further information, I attached the PDF files so that you can compare them.
Please let me know if there is any mistake.
I am looking forward
to hearing you soon. Thank you.
Best Regards,
Jin Ho Lee
Attachments:
GVU6E.pdf ‏44 KB
UMI7764.pdf ‏498 KB

9237 with full-bridge load cell: load cell_null_off_shuntcal.vi throws error 200077

Hi,
I'm trying to use the example
load_cell_null_off_shuntcal.vi with a full-bridge load cell (Honeywell
Model 31, unamplified). I am using LabView 8.6, cDAQ-9172 and NI9237. The
load cell is connected to pins 2,3,6 and 7.
The inputs for the VI front panel
are: internal excitation10V; mV/V 2.1492 (calibration sheet); max weight 10
lbs; bridge resistance 350 ohms (Honeywell specs); 9237 internal shunt
resistance 100 kohms; shunt location R4 (default setting). I have selected
"Do offset null" and "Do shunt cal".
This is the error I receive:
Error -200077 occurred at DAQmx
Perform Shunt Calibration (Bridge).vi:1 Possible reason(s):
Measurements: Requested value is not
a supported value for this property.
Property:
AI.Bridge.ShuntCal.GainAdjust
You Have Requested: -61.980405e3
Valid Values Begin with: 500.0e-3
Valid Values End with: 1.500000
If the "Do shunt cal"
green button is not selected, there is no error. I understand that the Gain
adjust value should be approx 1, whereas the one I get is much larger. The subVI DAQmx PerformShuntCalibration
(bridge).vi contains a "Call library function node" which I don't
know how to interrogate.
Has anyone else had experience
with this error? Do you have any advice on:
1)
How to "see" the calculations being
perfomed inside the "call library function node"?
2)
What the correct shunt element
location for a full bridge load cell is? (although changing this location does
not eliminate the error, I can't find this info).
3)
Anything I may be doing wrong with
my inputs to cause this error?
Thanks,
Claire.
Solved!
Go to Solution.

Hi Claire,
You have to physically connect the SC terminals to one arm of the bridge (normally R3). The terminal is not provided for connecting external resistors.
See example
C:\Program Files\National Instruments\LabVIEW 8.6\examples\DAQmx\Analog In\Measure Strain.llb\Cont Acq Strain Samples (with Calibration) - NI 9237.vi
"A VI inside a Class is worth hundreds in the bush"
യവന്‍ പുലിയാണു കേട്ടാ!!!

What is /INHIN1 terminal in the UMI-7764? It's not in the 7344 HW user manual.

What is the purpose of the /INHIN1 terminal and how does it relate to the Inhibit Output signal?

The basic purpose of the inhibit circuitry is to shut down the drive and inform other components in the system if a fault is detected. The UMI-7764 has circuitry onboard that will OR together four different sources of inhibits; the per axis controller inhibits, the per axis external inhibits (INHINx), the external inhibit all (INHALL), and the host bus interlock. You can use the INHINx lines to shut down an individual axis or the INHALL line to shut down all axes. These are typically wired to the "fault" output of the drive(s) you are using. When the UMI detects an inhibit from any of the four sources, then it will generate an inhibit signal on the INHOUTx lines. The INHOUTx lines are generally connected to the "enable" inputs on the drive(s). The polarity o
f the INHINx and INHOUTx lines is configurable using the switches on the UMI.
Do not simply tie any of these signals high or low with a jumper. Failure to properly connect the inhibit/enable signals can cause (and has caused) expensive damage to your motion system.
Cheers,
Brent R.
Applications Engineer
National Instruments

Load Cell Input UMI 7764

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