AMTI FAQs

Consult your Quick Start Guide! You can find a hard copy of this document in the AMTI binder that shipped with your amplifier or force plate. An electronic version can be found on the USB stick – also located in the AMTI binder. This is the quickest way to get you up and running.

If you cannot locate your Quick Start Guide, download it below for your corresponding force plate/amplifier model:

1. Check that the amplifier is connected to your computer via USB cable, and that is its connected to the force plate and powered on (you should see a green light).
2. Check that you have installed the drivers. Head to our Downloads Page for 32-bit and 64-bit drivers.
3. Check which version of NetForce you are running under the About menu. As of July 2015, the most up-to-date version is 3.6.4. If you have an older version it should be updated. Contact Us for the newest version. 
4. If this is an amplifier that was previously connected and working, check to make sure that the power supply is still working. If you have more than one amplifier, try replacing this power cord with one from a working amplifier.

Drivers for your AMTI USB products can be found on our Downloads Page. There are drivers for both 32-bit and 64-bit operating systems so be sure to choose the correct one for your operating system. The AMTI USB products include:

• GEN-5 amplifiers
• Optima amplifiers
• AccuSway-Optimized force plates
• AccuGait-Optimized force plates
• AccuPower-Optimized force plates

1. Make sure the amplifier and force plate are connected and the amplifier is powered on.
2. In the control panel search for the ‘Device Manager’ and open it.
3. Locate the AMTI device (it will likely be listed under 'Other Devices' and have a warning on its logo).
   • If you are using a GEN-5, it will appear as ‘GEN 5’.
   • If you are using an OPTIMA amplifier, it will appear as ‘HPS-SC’.
   • If you are running an AccuGait-O/AccuSway-O/AccuPower-O, it will appear as ‘ACG-O’, ‘ACS-O’, or 'ACP-O' respectively.
4. Right click and select ‘Update Driver Software …’
5. Select ‘Browse my computer for driver software’.
6. Click ‘Browse’ and navigate to the folder containing the driver files. Make sure to select the appropriate 32-bit or 64-bit version for your operating system and then click ‘OK’.
   • To determine which operating system you have, under the Windows Start Menu click ‘Computer’, then right click and select ‘Properties’.
7. The drivers should install.

For more details on the driver installation, consult your User Manual or Contact AMTI Support.

AMTI's patented Optima calibration is a revolutionary development in force measurement technology. The calibration of an Optima system is an exacting process involving up to 4000 measurements taken over the entire working surface. Multiple loads are applied at up to 400 locations using a precision machine capable of maintaining absolute positioning accuracy of 0.005 mm.

Using AMTI’s new optimized strain gage technology, the Optima-HPS force plate model provides levels of accuracy never before seen in force platform systems:

• Average COP accuracy of just a fraction of a millimeter (typically less than 0.2 mm)
• Crosstalk values typically ±0.05% of applied load
• Measurement accuracy typically ±0.1% of applied load*

Check out our Optima Technology page for more information.

Optima gains it superior accuracy in large part from its unique calibration procedure that adjusts for variability over the surface of the force plate. As a result, our Optima force plates do not have a simple 6x6 element calibration matrix, as you might be used to with traditional legacy force plates. Optima's in-depth calibration requires a complex mathematical process to convert from voltages to engineering units.

This complex mathematical conversion is performed automatically within the Optima amplifier. This occurs whether you are using the analog or digital output signal.

The simplest way to take advantage of the high accuracy of the Optima system is by using the digital signal, which sends computed forces and moments to any software program that supports our USB integration. In this case, you do not need to input a calibration matrix (6x6 or otherwise) into your third party software at all as everything is handled within the amplifier. (If you are a software company interested in integrating AMTI force plates, contact AMTI for our SDK).

If digital integration is not an option, see FAQ: How do I set up my Optima force plate in analog mode? below.

The calibration file for an AMTI Optima force platform is stored in the form of a .bcf file. When setting up a new Optima force platform, AMTI's NetForce software will give you the option to Browse and navigate to the AMTI USB dongle that shipped with your system. Here you can select the Optima nnnnm.bcf file for your force platform from the Calibration folder. By uploading this .bcf file, it will automatically save it to the C:\AMTI\HPS directory on your PC. The AmtiSystemConfig software always searches this directory first for calibration files to download when new Optima platforms are detected.

This process only needs to be performed the first time you are setting up this specific combination of force platform and Optima amplifier on your PC. The .bcf file will be downloaded to your Optima amp for future use each time you initialize this force platform & amplifier.

For analog integration with an Optima system, use the Fully Conditioned analog output mode set in NetForce. Download the technical document below for steps to set up Fully Conditioned mode.

With Fully Conditioned mode, all signal conditioning features are enabled and the Optima amplifier converts the voltage signals from the plate to engineering units within the amplifier. Then, in order to output from the amplifier as an analog signal, Analog Scale Factors are used to convert the signal back to a voltage.

With AMTI's Optima force plates, the "electrical" origin is at the geometric center of the top surface of the platform. Therefore, the offsets are (0, 0, 0). Be sure to account for the thickness of any flooring material on your force plate, however.

Each AMTI Optima mountable force platform system ships with a complete mounting kit including: Aluminum mounting rails, epoxy-resin, and other tools for levelling, epoxying, and securing down your force plates. The mounting rails will first need to be precisely levelled, after which the epoxy-resin can be used to secure the rails to the underlying concrete (either in the base of a pit or on top of a slab). After levelling and adhering your mounting rails to the concrete with the epoxy, the force plates will simply bolt down to the rails via through-top mounting access holes to complete the installation.

Each AMTI Optima mountable force platform system ships with a complete mounting kit including: Aluminum mounting rails, epoxy-resin, and other tools for levelling, epoxying, and securing down your force plates. The mounting rails will first need to be precisely levelled, after which the epoxy-resin can be used to secure the rails to the underlying concrete (either in the base of a pit or on top of a slab). After levelling and adhering your mounting rails to the concrete with the epoxy, the force plates will simply bolt down to the rails via through-top mounting access holes to complete the installation.

For an efficient installation, we advise oversizing the length and width of your pit by at least 6" on all sides around the anticipated footprint of your force platform array. We recommend this because the force plates require a 1/8" gap between them and any surrounding flooring, pit walls or surfaces in order to remain completely isolated and therefore measure properly. It is very difficult to construct a "zero clearance", right-angle pit that is precisely 1/8" larger than the force plates, such that the force plates will be completely isolated once installed.

With AMTI's recommended method, the force plates and mounting rails would be installed centered in the pit, after which a structure (designed and fabricated by the customer or contractor; wood or other) can be used to fill in the perimeter space around the force plates in the pit. This structure can be used to ensure the 1/8" gap around the force plates is maintained everywhere.
(See Diagram of Pit Finish Details pdf below)

Contact AMTI to request a technical document reviewing our recommendations for pit design, including:

• Pit length x width x depth
• Flatness and levelness of concrete (base & upper perimeter of pit)
• Conduit requirements

Visit our Installation Services page for more information.

Before beginning any construction work, contact AMTI to request our technical document outlining requirements & recommendations for the design and fabrication of your pit (or other) where you plan to install your force plates. The documentation provided reviews required pit LxWxDepth, flatness/levelness of concrete, conduit specs, etc. Visit our Installation Services page for more information.

After pit fabrication has been completed and prior to the installation of your force plates, conduct or obtain a survey of the installation area (whether concrete pit or on top of slab). The purpose of this survey is to confirm that the concrete flatness and levelness (and depth in many cases) meet the specificaions for your force plate model.

See Sample Survey Diagram & Form and Pit Depth Survey (AMTI) PDFs below for illustrations & steps for surveying your pit/site.

This survey is required for if/when AMTI is to perform the installation of your force plates, and recommended if the customer or contractor is to perform the installation. For AMTI installations, we require that a pit survey and Field Installation Questionnaire be completed and approved by AMTI at least 2 weeks prior to the installation date.

Contact AMTI for more detail.

Your force plate systems will ship with all of the mounting equipment and instructional manuals that you would need to complete the installation yourself or by your contractors. AMTI also offers installation services by our experienced team of in-house technicians, who can ensure your force plate systems are installed precisely and successfully.

Visit our Installation Services page for more information.

AMTI's force plate systems have adjustable settings that allow you to optimize the working range of your system to your needs. If one or more of your channels is saturating, this can typically be solved by reducing the Gain setting on your amplifier for that channel(s).

Reducing the Gain by half will double the working range of your force plate. Please note that you should never load the plate above its mechanical capacity.

You can review the mechanical capacity of each channel for your given force plate model by navigating to its product page through our Force Plate Landing Page or using the Search menu.

How to change the Gain (and Excitation Voltage) of your force plate system:

Gen 5 or Optima amplifiers

The settings for these amplifiers are software-configurable through AMTI's NetForce program.

1. In NetForce under the ‘Setup’ menu, select ‘Hardware Installation’ and then click ‘Modify’
2. For the force plate and amplifier of interest, click on the button listed under ‘Configure’ in the list of ‘Installed Amplifiers’
3. In the ‘Amplifier Configuration SN: XXXX’ window, set the ‘Excitation’ and ‘Gain’ to appropriate values for each channel
   • Typically the Excitation Voltage should remain at 10V
   • Reduce the Gain to increase the force-measuring range of your system
4. Click ‘Apply’ then ‘OK’
5. Click ‘Save’ in the next window

Digital Integration (Gen 5/Optima)

If you are using digital integration or recording in NetForce, you will be all set after completing Steps 1-5 above.

Fully Conditioned Analog (Gen 5/Optima)

If you are using Fully Conditioned Analog output mode, you need to make additional adjustments before the Gain and/or Excitation changes will be reflected in the analog output of your amplifier, as well as in any third party software.

For details on how to do this, refer to the General Fully Conditional guide below (starting at Step G) or one of the guides for a specific third-party software.

This means that your force plate is saturating (or overloading) on one or more channels. Usually, you are simply hitting electrical saturation due to the current settings you have for your amplifier. If this is the case, it can easily be solved by adjusting your amplifier settings. Information on how to do this can be found in the questions above: One or more channels on my force plate are saturating. What should I do?

When the orange Autozero light on your amplifier is constantly illuminated this indicates a break in the connection between the amplifier and the force plate on one or more channels. This could be the result of a loose connection, damaged cable, bent pin on a connector, etc.

As a first step try pressing the Autozero light/button. It should blink. If it goes out after blinking you are all set and should be fine to continue using your system.

If the orange Autozero light on your amplifier remains constantly illuminated, this indicates a break in the connection between the amplifier and the force plate on one or more channels. This could be the result of a loose connection, a damaged cable, a bent pin on a connector, etc.

Troubleshooting steps:

• Make sure all connections are secure between the force plate and the amplifier.
• Check the connectors on the cable, amplifier, and force plate itself (particularly the male connectors) for any damage or bent pins. 
• If you have more than one system, try systematically swapping out each component one at a time to determine which is causing the issue (cable, amplifier, or force plate).
  • Swap in a different cable that you know is functioning properly to see if the cable is the issue.
  • If the cable is not the problem swap out the amplifier to see if that solves the issue.
  • If the amplifier is not the problem, swap out the force plate.

If you would like to work through this process in conjunction with someone from AMTI, please contact us for assistance.

If this is the first time you are setting up your system, please refer to the FAQs above under the section General Setup and Software Configuration.

If your force plate was previously working but is no longer showing up in NetForce, double-check the cable connections, then check if the system is being recognized by your computer in the 'Device Manager'.

1. Click on the windows start menu (bottom right of your desktop) and type "Device Manager’ into the search. Click on 'Device Manager' in the search list to open it.
2. Expand the 'Universal Serial Bus Controller' category and search the list for your AMT equipment (Gen 5, HPS-SC, ACG-O, ACS-O, ACP-O, etc). If you don’t find it there, check if there is a category for 'Other Devices' and if the AMTI equipment is listed there.
   • If you find your device under 'Other Devices' refer to the instructions above: How do I install the drivers for my force plate system?
3. If you cannot find your AMTI device in either location, try turning the amplifier off for several seconds and then back on while looking at the Device Manager list. If the amplifier is being recognized by your computer, you should see the list refresh.
   • If the list is not refreshing, then the computer is not recognizing the AMTI device. Keep reading below for tips on how to troubleshoot this issue

If your AMTI equipment is not appearing in the Device Manager:

• You could have a bad power supply on your amplifier. If you have more than one system, try swapping in a power supply from another system to see if this solves the issue.
• Try switching the USB cable to a different USB port on the computer.
• If you are connecting more than one force plate, make sure that the USB hub you have is connected to external power. Also try connecting one force plate system at a time, directly to your computer.

If you are still having trouble, contact AMTI for assistance with additional troubleshooting steps.

If you are getting this error when connected to a blue Optima force plate, your amplifier is not reading the force plate's stored information correctly, for one reason or another.

This could be due to a loose connection between your force plate and amplifier – so check this first! Turn off the amplifier then disconnect and reconnect the cable between your force plate and amplifier.

With the amplifier still off, exit the NetForce software if you have it open. Restart Netforce and run through the steps to find your amplifier. If you don’t know how to do this, refer to the question above “I just received my force plates, how do I set them up?” in the section: General Setup and Software Configuration.

Hopefully after running through these steps your force plate is now showing up as an Optima plate and you can continue with the setup process. If you have any trouble feel free to reach out to AMTI for assistance.