What to do when you get an error message

Have you received an error message? Make sure you always use the latest version of LogTag Analyzer. This will solve in most cases the errors you have, including the "$1 internal error". This error occurs when the software is trying to communicate with a model that is newer than your current version of LogTag Analyzer supports.

Update your software via LogTag Analyzer by going to "Help" and "Check internet for updates". Or visit our website to download the latest software version. If you’re currently running an older version, the software will automatically update your version.

An error message can also be the cause of a low battery. Check your battery life to be sure.


Errors “Cannot connect to Logtag…” or “$4:USB.0012345” or “failed to respond [20]”

Have you received any of these error message; “Cannot connect to Logtag…or$4:USB.0012345” or “failed to respond [20]” or simply error [20]?

These are very general error messages which simply mean that LogTag Analyzer found an interface and detected the presence of a Logger inside the interface but was unable to establish communication. The letters and numbers after $4 represent type and serial number of the interface.

Often this error will disappear by simply repeating the action you were performing when the error occurred, but sometimes it can be a bit more difficult to locate the cause. Here are some scenarios in which these errors could occur and what to do to rectify the issue:

  • There is poor electrical connection between the Logger contact pads and the interface pins; this can happen if the contact pads are dirty or have been exposed to a corrosive environment. Usually this can be corrected by cleaning the contact pads on the Logger. Use a soft, damp cloth. For stubborn stains you can also use a soft pencil eraser.
  • There is a "stuck" contact pin inside the interface; look inside the slot, there should be three contact pins visible, they should slide in and out with moderate resistance when force is applied (e.g. with the end of a pencil). Make sure all pins move freely.
  • There is not enough power being supplied to the interface (USB); We have seen this error when USB interfaces are used on unpowered USB hubs with other equipment also connected. USB ports have a limited ability to supply power and we would always recommend to connect the USB interfaces directly to the computer or to use a powered hub.
  • Communication has been interrupted prematurely; sometimes a user will remove the Logger from the interface too early, which will cause this error to be displayed. In this case simply re-do the action with the Logger connected properly throughout the communication.
  • The USB port is defective; try a different port and see if the error persists.
  • The Logger battery is critically low.
  • The LogTag has just been removed from a cold environment. Lithium cells and in fact all batteries typically exhibit a lower battery voltage in cold conditions, sometimes significantly lower, so downloading units that have come e.g. directly out of a freezer could show communication problems. In that case it may pay to wait until the unit has acclimatised to room temperature or slightly above.
  • There was water in the unit; different Logger models have different water damage protection and are not waterproof. If water got inside the unit, it will keep working for a time, but eventually the communication will cease to work.
  • The Logger has been subjected to strong EMC fields or radiation, causing a corruption in its internal memory.


It means that the Logger interface cradle is working correctly but the communication between the interface cradle and Logger is not working.

This FAQ covers this error in more detail:


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