Air Brakes and Train Handling Rules - Alaska Railroad

68 EOT Telemetry Devices68.3.4 LCU Operational CheckTest whether the LCU is operational using a manual or automatictest.A. Manual TestTo manually test the LCU:1. Make sure the EOT is installed correctly and connected to thebrake pipe (see Rule 68.2.1, Installing the EOT Unit).2. Set the LCU ID code thumbwheel switches to match the ID codeof the EOT being used for testing (see Rule 68.3.3A, ControllingLocomotive).3. Press and release the DISPLAY TEST button on the LCU.NOTE: If all LED indicators and displays light up, thedisplay test is successful.4. Test the front-to-rear and rear-to-front radio links by pressing theCOMMUNICATIONS TEST/ARM button on the LCU. Makesure COM TEST appears in the message display window.NOTE: If the communications test is successful, COM OKwill replace COM TEST in the message display window. Ifthe communications test is not successful, NO COM will bedisplayed for 5 seconds.B. Automatic TestThe LCU automatically sends a status update request to the EOTevery 10 minutes, testing the radio links in both directions. Sincethis test is ongoing, no indications appear on the LCU display if thetest is successful. During the test:1. If an EOT reply is not received within a designated time period,the LCU sends another request 15 seconds later.2. If the EOT does not respond to this retry, the LCU sends anotherrequest 6 minutes later.68-12 ARRC Air Brakes and Train Handling Manual June 1, 1996