Use proper power cord.

Use only the power cord specified for this product and certified for the country of use. Do not use the provided power cord for other products.

Ground the product.

This product is indirectly grounded through the grounding conductor of the mainframe power cord. To avoid electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output terminals of the product,ensure that the product is properly grounded. Do not disable the power cord grounding connection.

Power disconnect.

The power cord disconnects the product from the power source. See instructions for the location. Do not position the equipment so that it is difficult to operate the power cord; it must remain accessible to the user at all times to allow for quick disconnection if needed.

Observe all terminal ratings.

To avoid fire or shock hazard, observe all rating and markings on the product. Consult the product manual for further ratings information before making connections to the product.

Do not operate without covers

Do not operate this product with covers or panels removed, or with the case open. Hazardous voltage exposure is possible.

Avoid exposed circuitry

Do not touch exposed connections and components when power is present.

Do not operate with suspected failures.

If you suspect that there is damage to this product, have it inspected by qualified service personnel.

Disable the product if it is damaged. Do not use the product if it is damaged or operates incorrectly. If in doubt about safety of the product, turn it off and disconnect the power cord. Clearly mark the product to prevent its further operation.

Examine the exterior of the product before you use it. Look for cracks or missing pieces.

Use only specified replacement parts.

Do not operate in wet/damp conditions

Be aware that condensation may occur if a unit is moved from a cold to a warm environment.

Do not operate in an explosive atmosphere

Keep product surfaces clean and dry

Remove the input signals before you clean the product.

Provide proper ventilation.

Refer to the installation instructions in the manual for details on installing the product so it has proper ventilation.

Slots and openings are provided for ventilation and should never be covered or otherwise obstructed. Do not push objects into any of the openings.

Provide a safe working environment

Always place the product in a location convenient for viewing the display and indicators.

Be sure your work area meets applicable ergonomic standards. Consult with an ergonomics professional to avoid stress injuries.

Use care when lifting and carrying the product. This product is provided with a handle or handles for lifting and carrying.

To avoid electric shock

Do not touch exposed connections.

Do not service alone

Do not perform internal service or adjustments of this product unless another person capable of rendering first aid and resuscitation is present.

Disconnect power

To avoid electric shock, switch off the product power and disconnect the power cord from the mains power before removing any covers or panels, or opening the case for servicing.

Use care when servicing with power on

Dangerous voltages or currents may exist in this product. Disconnect power, remove battery (if applicable), and disconnect test leads before removing protective panels, soldering, or replacing components.

Verify safety after repair

Always recheck ground continuity and mains dielectric strength after performing a repair.

Upgrade the instrument firmware

You can upgrade the instrument firmware as follows.

1. Insert a USB stick with the firmware into the intrument USB port.
2. Cycle the power.
3. Verify that the instrument firmware was updated by checking the displayed software version in the Instrument Health panel.

Example setups

Eye diagrams

As part of the DUT Tx tests, eye diagrams are shown for each lane and preset combination that represent the error-free region of the link formed between the DUT and the Margin Tester.

The eyes are shown in real-time, which means it only takes seconds before results begin to display.

Link training parameters

The Margin Tester shows not only the performance of the link by displaying eye diagrams, but also displays how the Margin Tester’s receivers were adjusted to maximize the generated eye. Some eyes may need especially high levels of equalization in order to form the link, so having both pieces of information is critical to understanding performance. The Margin Tester displays a table showing the Attenuation, VGA (Gain), CTLE, and 5 DFE taps values used to maximize the eye opening. This allows you to quickly see how much equalization is needed for each displayed eye diagram. The possible range of values for each of these equalization settings is shown in the following table.

If an eye is wide open, but the equalization settings are pushed to their maximum, it may indicate there are some performance considerations for that given lane and preset combination.

Quick scan Rx test

The quick test consists of a link train between the Margin Tester and DUT, where the DUT selects the presets for communication. The Margin Tester then steps down the transmitted amplitude by dropping the main cursor value by lane/preset, within an expected range of operation.

This provides a high-level evaluation of Rx performance quickly, which can help you determine if there are any problem lanes that may be worth investigating further with other equipment. If no errors are indicated, this is considered a functional pass. If errors are indicated, the main cursor value where the error occurred is displayed, and the test is considered a functional fail.

Custom scan Rx test

In the custom test, the receiver DUT requests of the TMT4 transmitter any valid combination of cursor coefficients on any and all lanes. This means that anything that the receiver under test requests can be tested.

When the receiver test is running, the TMT4 uses cursors to decrease the amplitude, but does not limit the test to a range. Instead, it pushes the receivers as far as they will go until an error is registered. It then reports back both the main cursor value and % in amplitude reduction at the point of failure. You can add a custom amplitude threshold value on the Custom Scan setup screen to assist in highlighting lanes that do not meet acceptance criteria.

Understanding the DUT Rx test

The Rx test decrements the TMT4's Tx Eq. main cursor by one, repeatedly, along with proportional adjustments to the pre and post cursors, until the link is lost.

The amount that the main cursor can be lowered is expressed as a percentage of the starting main cursor value; therefore, the larger the number, the better.

You can add a pass/fail limit on the Custom Scan setup screen to help highlight lanes that do not meet your acceptance criteria.

If the measured amplitude reduction exceeds the user-specified limit, then the result is displayed in black text. If not, it is shown in red text.

Set up and run a Quick Scan

You can run a Quick Scan from the Web interface as follows.

1. Click the Setup button and then set the Test Type to Quick Scan.
2. Set the Generation (PCIe 3 or PCIe 4).
3. Click the Run Scan button.

You can run a Quick Scan from the front panel as follows.

1. Set the Generation (PCIe 3 or PCIe 4).
2. Click the Run Quick Scan button on the display screen.

Results

The approximate test time for Gen 4 x16 links is 2-4 minutes. Once the test begins, the Results Test Status screen will automatically be displayed.

There are three results pages on the front panel. Each page contains a Home button, a Save button, and a Help button. The Save button will save results to a USB stick connected to the TMT4.

• Page 1: All scanned lanes along with the Tx preset, Tx eye width, Tx eye height, Rx preset, and Rx C0
• Page 2: Tx link training parameters
• Page 3: Eye diagrams

The three results areas on the Results panel in the Web interface are shown in the following image.

• For a DUT Tx test, the results show the resulting eye diagrams at the receiver of the TMT4 instrument, and the associated link training parameter values that show the equalization used at the TMT4 receivers to open the eyes.
• For a DUT Rx test, the results table shows the preset each lane is trained to, the expected test range based on the negotiated preset, and if any errors were found.

Set up and run a Custom Scan

You must use the Web interface to set up Custom Scan parameters. Set the following as desired for your testing needs.

Select Run Scan to run the scan after the parameters have been set. You can select DUT Tx Test or DUT Rx Test to run. For a Tx test, select the desired presets to test.

For the Rx test, select the test limits. You can add a custom amplitude threshold value on the Custom Scan setup screen to assist in highlighting lanes that do not meet acceptance criteria.

Custom Scan results

The approximate test time for Gen 4 x16 all lanes/presets is 25-30 minutes.

The Custom Scan results page provides a tiered results structure where data can be expanded and collapsed based on the generation tested or by the type of test in a specified generation. Both the Tx eye diagram and the link training parameter table results can be configured to view the results by lanes tested or by presets tested. This allows you to quickly view results across all charts and draw conclusions as to the performance of any given lane or preset grouping for up to 160 lane-preset combinations.

Sub-state information

The LTSSM Setup window shows a graphical representation of the State Machine diagram for PCIe devices. Sub-state information is available for the Detect, Polling, Configuration, and Recovery states. To access the sub-state information, do the following.

1. Hover over the desired LTSSM Major State.
2. Click the chosen state to display the sub-state information.
3. Click the Back button to return to the main LTSSM states diagram.

Setup and run LTSSM Monitor test

To configure and run the LTSSM Monitor Test in the Web UI, do the following.

1. Select Setup and then click the option next to LTSSM Monitor.

   
   
   
2. Select the appropriate clock setting under Link Settings.
3. You can select a manual start/stop or a triggered start for the test.

   1. Select Manually to allow for test start when you click the Go button at the bottom of the screen.

      Test stop will be set to occur when you click the Stop button.

   2. Select Trigger In to allow for test start from an externally provided hardware trigger. The Trigger In becomes active on a HIGH to LOW transition. (See the TMT4 Specifications and Performance Verification Technical Reference on tek.com for further trigger information.)

      Select After and set a specified amount of time in seconds, minutes, or hours after trigeer start to stop the test.

4. Trigger Out: If no trigger out signal is required, select None.

   
   
   

   Any other selection will generate a trigger out hardware signal when one of the following valid test conditions is selected.

   • State Entry or Exit: select one of 11 available States.
   • State Transition: Select a From State and a To State.
   • State Duration: Select the minimum time to satisfy the condition.
5. Link Speed: This menu item appears for all of the above conditions except None. Select Any or the desired link speed.

Time for completion of a LTSSM test includes the user selected test time (for example, 10 s) plus additional processing time that is required for the data to be collected and compiled, such that the overall elapsed time can be a few seconds longer than the actual test.

LTSSM Monitor test results

Select the Results button to view the test results. In the Results window, you can view the % of time the link was in specific states and the count of state transitions.

The maximum test time of LTSSM events is limited to 6.5 hours.

Use the Save/Recall button in the left panel to save or recall files.

Format and send a login request

First you send a login request and then you send an authentification token. An authentification token is required to use any endpoint that changes the state or accesses certain information about the Margin Tester.

Format and send a Custom Scan request

Custom scans can be configured to specify which lanes, presets, and PCIE generations to scan. You can also set the Pass/Fail limits for TX eye height and eye width.

• A scan can be divided into multiple tests. A test is a Tx or Rx test with a given Generation (Speed) and Clock settings.
• This example is a scan with two tests. This first test is running on Generation 3 and the second test is running on Generation 4.
• In this example, both Tx and Rx tests will run for Generation 3 with all lanes and presets enabled for both tests, with SSC disabled. In the Generation 4, only a Tx scan is specified to run for lanes 0-3 for preset 5.

Monitor the progress of a scan

1. Ping the Status endpoint to get the current status of the Margin Tester.
2. View the 'teststatus' key in the return object to view the current test status.
3. When 'teststatus' is either Aborted or Finished, scan is complete.

Download and extract Scan results

Results are returned in the form of a .zip file containing CSVs, charts, and more. You can either open the zip file and view the results as-is, or recall the zip file to the Web interface through the Save / Recall page.

Format and send a login request

First you send a login request and then you send an authentification token. An authentification token is required to use any endpoint that changes the state or accesses certain information about the Margin Tester.

Initialize Quick Scan

• Quick Scan performs both a Tx and Rx test on all available lanes.
• Only PCIe Generation (Speed) is user-configurable. All other test configurations (lanes, presets, pass/fail limits, etc) are selected automatically.
• Quick Tx test lets all available lanes train to their preferred preset and reports Eye Widths, Eye Heights and Receiver Settings.
• One and only one preset is selected per lane. Maximum eye count is 16.

Monitor Scan Progress

1. Ping the Status endpoint to get the current status of the Margin Tester.
2. View the 'teststatus' key in the return object to view the current test status.
3. When 'teststatus' is either Aborted or Finished, scan is complete.

Download and Extract Scan Results

Results are returned in the form of a Zip file containing CSVs, charts, and more. You can either open the zip file and view the results as-is, or recall the zip file to the Web UI via the Save / Recall page.