7.1. Troubleshooting

General Troubleshooting

If the MeasureReady™ M81-SSM is not operating properly, try the following solutions.

  1. Refer to the list of error messages

  2. Cycle the power

  3. Reset the instrument to factory defaults

  4. To determine whether the issue is with the module or the instrument, test the instrument with a different module, or try disconnecting and reconnecting the module

  5. If none of these solutions work, contact Lake Shore Service

General Remote Interface Troubleshooting

Timeouts during range changes

The M81-SSM will not return a measurement while settling between range changes. If a module is configured with a long averaging time (large number of NPLCs) and/or is transitioning through multiple ranges, it may take multiple or even tens of seconds before a measurement is returned. Either increase the remote interface timeout setting or poll the settling status bit to avoid querying during settling.

USB Troubleshooting

This section provides USB interface troubleshooting for issues that arise with new installations, existing installations, and intermittent lockups.

New Installation

  1. Check that the instrument’s interface is set to USB.

  2. Check that the USB driver is installed properly and that the device is functioning. In Microsoft Windows®, the device status can be checked using Device Manager by right-clicking Lake Shore Instrument under Ports (COM & LPT) or Other Devices and then clicking Properties.

  3. Check that the correct com port is being used. In Microsoft Windows®, the com port number can be checked using Device Manager under Ports (COM & LPT).

  4. Check that the correct settings are being used for communication.

  5. Check cable connections and length.

  6. Send the message terminator.

  7. Send the entire message string at one time including the terminator. (Many terminal emulation programs do not.)

  8. Send only one simple command at a time until communication is established.

  9. Be sure to spell commands correctly and use proper syntax.

Existing Installation No Longer Working

  1. Power the instrument off, then on again to see if it is a soft failure.

  2. Power the computer off, then on again to see if communication port is locked up.

  3. Check all cable connections.

  4. Check that the com port assignment has not been changed. In Microsoft Windows®, the com port number can be checked in the Device Manager window, under the Ports (COM & LPT) device type.

  5. Check that the USB driver is installed properly and that the device is functioning. In Microsoft Windows®, the device status can be checked using Device Manager by right-clicking Lake Shore Instrument under Ports (COM & LPT) or Other Devices and then clicking Properties.

Intermittent Lockups

  1. Check cable connections and length.

  2. Increase delay between all commands to 100 ms to make sure instrument is not being overloaded.

  3. Ensure that the USB cable is not unplugged and that the M81-SSM is not powered down while the com port is open. The USB driver creates a com port when the USB connection is detected, and removes the com port when the USB connection is no longer detected. Removing the com port while in use by software can cause the software to lock up or crash.

IEEE Interface Troubleshooting

This section provides IEEE interface troubleshooting for issues that arise with new installations, old installations, and intermittent lockups.

New Installation

  1. Check the instrument address.

  2. Always send a message terminator.

  3. Send the entire message string at one time including the terminator.

  4. Send only one simple command at a time until communication is established.

  5. Be sure to spell commands correctly and use proper syntax.

  6. Attempt both Talk and Listen functions. If one works but not the other, the hardware connection is working, so look at syntax, terminator, and command format.

Existing Installation No Longer Working

  1. Power the instrument off, then on again to see if it is a soft failure.

  2. Power the computer off then on again to see if the IEEE card is locked up.

  3. Verify that the address has not been changed on the instrument during a memory reset.

  4. Check all cable connections.

Intermittent Lockups

  1. Check cable connections and length.

  2. Increase the delay between all commands to 50 ms to make sure the instrument is not being overloaded.