The EM31MK2 has gone though many revisions over the life span of the product. When Geonics moved to using third party data loggers like the Allegro, Archer, Archer2 and now rugged tablets with Windows OS the digital LCD display was removed which indicated if the batteries were completely depleted. The result of this was that it became harder to determine if the batteries were flat, installed incorrectly or if the Bluetooth settings were incorrect. Since 2018 Geonics have been installing LED on the EM31MK2 which indicates if the batteries have sufficient power.
If your EM31MK2 is Bluetooth enabled and use one of the data loggers listed above then we suggest keeping it simple can connecting via the EM31MK2 to serial cable first.
Turn the EM31MK2 to Opp and the gain switch to Batt.
Note the Transmitter and Receiver do not need to be connected to run this test.
Navigate to the Nav31 or RTMap31 program on your device and change the EM31 port setting to Com1 under the Logger Setup menu. Make sure the EM31 is enabled. Next navigate to the GPS Setup Menu and disable the GPS for the time being.
Navigate back to the program main menu and click on Logging. If the ‘Cannot Open EM31MK2 serial Port’ message is displayed then remove the battery cradle from the EM31MK2 and check there is no corrosion on the contacts and all contacts are in firm contact with the battery terminals. Also check that none of the batteries are installed the wrong way round. If all appears in good order replace the batteries with a new set.
If the error message is not displayed, check C and I read >4.4V. As long as these values are greater than 4.4V the batter power is sufficient and the issue lies with the Bluetooth com port allocation.
Please refer to our Bluetooth troubleshooting guide under the FAQs for further guidance.