Controller Disconnects During Long Tests - Check Windows Power Management

If the Spider disconnects during long tests, Windows power settings are a likely cause. This page shows how to change them.

The disconnect often happens overnight or after the PC has been left alone for a while. EDM shows the front-end as disconnected, and the test stops or aborts. The connection comes back after you reconnect the cable, restart EDM, or wake the PC. It happens most often when the Spider is connected through a USB-to-Ethernet adapter, a USB-C dongle, or a docking station.

Windows saves power by turning off devices it thinks are idle. A USB-to-Ethernet adapter can be suspended, or lose power when the PC goes to sleep. Some adapter power-saving features can also drop the link. Energy-Efficient Ethernet normally keeps the link up, but with some adapters and drivers it can cause disconnects.

You can usually fix this yourself with the steps below. Do not make these changes while a test is running. If you have not set up the network connection yet, see Connecting the Spider System to the PC first.

First find the adapter that connects to the Spider:

1. Press Windows + R, type ncpa.cpl, and press Enter.
2. Right-click an Ethernet adapter and click Status.
3. Click Details and look at IPv4 Address. The adapter that connects to the Spider has an address in the Spider subnet (for example 172.0.0.x or 169.254.x.x).
4. If it is not the right adapter, close the windows and check the next Ethernet adapter.
5. Write down the device name. It is shown under the adapter name in Network Connections. USB adapters usually have “USB” in the device name, for example Realtek USB GbE Family Controller or ASIX AX88179 USB 3.0 to Gigabit Ethernet Adapter.

Then change its power-saving options:

1. Right-click Start and click Device Manager.
2. Expand Network adapters.
3. Right-click the adapter and click Properties.
4. Click the Advanced tab.
5. For each property in the table below that is in the list, select it and set Value to OFF.
6. Click OK.

Not every adapter has all of these properties. Change the ones that are there and leave the others.

The adapter may disconnect for a few seconds when you click OK. This is normal.

1. In Device Manager, right-click the adapter and click Properties.
2. Click the Power Management tab.
3. Clear the Allow the computer to turn off this device to save power check box.
4. Click OK.

Some PCs do not show the Power Management tab for some adapters. If the tab is not there, try the next section.

If the adapter is connected by USB (for example a USB dongle, or a USB-C dock or hub), also do this for the USB devices between the adapter and the PC:

1. In Device Manager, click View > Devices by connection.
2. Expand the items until you find the adapter.
3. Look at the items above the adapter in the tree, for example Generic USB Hub, USB Root Hub, and USB eXtensible Host Controller.
4. For each of these items that has a Power Management tab, open Properties and clear the same check box.
5. Click View > Devices by type to go back to the normal view.

You do not need to change USB hubs that the adapter is not connected to.

Do this if the adapter is connected by USB.

1. Press Windows + R, type powercfg.cpl, and press Enter.
2. Next to the selected power plan, click Change plan settings.
3. Click Change advanced power settings.
4. Expand USB settings > USB selective suspend setting.
5. Set Plugged in to Disabled.
6. Click OK.

1. Click Start > Settings > System > Power & battery (on a desktop PC: Power).
2. Expand Screen, sleep, & hibernate timeouts.
3. Under Plugged in, set the sleep setting (on a desktop PC: Make my device sleep after) to Never.
4. If there is a hibernate setting, set it for Plugged in to Never.

The screen can still turn off. Only sleep must be Never.

1. Restart the PC.
2. Run a test under the same conditions as the test that failed: the same adapter, dock, and USB port, and the same test length.
3. Do not use the PC for other work during this test.
4. Confirm that the test finished without a disconnect.

If the Spider still disconnects after you try these steps, email Crystal Instruments support at support@go-ci.com. Include:

• The date and time of the disconnect.
• The device name of the adapter that connects to the Spider.
• The EDM log files (see Sending the Tech Support Log File).

If you can, also try a different USB-to-Ethernet adapter or the PC's built-in Ethernet port.