Introduction to Tach Time

Tach Time is calculated based on the average cruise RPM for your aircraft. Tach Time is accumulated once per second, using the following calculation:
Tach Time = Tach Time + (Current RPM / Average Cruise RPM).
Tach Time is true (counting at 1:1 with HOBBS), when your current RPM is at the Average Cruise RPM setting in the EDM.
When your RPM is less than Average Cruise RPM (when taxiing, decent, etc), Tach Time will count slower than HOBBS Time.
When your RPM is higher than Average Cruise RPM (during takeoff, climbing, etc), Tach Time will count faster than HOBBS Time.
Calibrating Tach Time

When shipped from the factory, your J.P. Instruments EDM will be set with Average Cruise RPM = 2400.
If your aircraft’s average cruise RPM is not 2400 RPM, follow these steps to set the Average Cruise RPM value.
With the engine off, enter Pilot Program Mode by holding STEP and LF for 2 seconds.
Tap NEXT repeatedly until END? is displayed.
Tap the FACTORY button, or hold STEP and LF for 2 seconds.
Tap NEXT until AVERAGE CRUISE RPM is displayed
Hold the left 2 buttons for 2 seconds to allow modification of the Average Cruise RPM.
Tap PLUS or MINUS to modify the RPM value.
When the value is properly set, hold the left 2 buttons for 2 seconds to save changes.
Tap NEXT until END? is displayed.
Tap YES to restart the EDM.
Important: Be sure to set AVERAGE CRUISE RPM in the first 10 hours of operation. After 10 hours of operation, the Average Cruise RPM setting will be locked down to prevent tampering with Tach Time values.

Fuel Used Reminder Feature

Introduction

In order to assist the pilot with fuel tank management, EDM730/830 and EDM740 units now have the ability to display a reminder when a preset amount of fuel has been burned during this flight. For example: if the EDM “Gallons Used Reminder” is set to 10, when 10 gallons of fuel have been burned since startup, you will see a reminder message on the EDM like “REMINDER: 10 GAL BURNED.” The reminder message will be displayed for five seconds and cleared, or can be cleared immediately by tapping the STEP key.

Configuring Fuel Used Reminders

When shipped from the factory, your J.P. Instruments EDM will be set with Fuel Used Reminders disabled.

To enable Fuel Used Reminders:
With the engine off, enter Pilot Program Mode by holding STEP and LF for 2 seconds.
Tap NEXT repeatedly until END? is displayed.
Tap the FACTORY button, or hold STEP and LF for 2 seconds.
Tap NEXT until GALLONS USED REMINDER=0 is displayed.
Tap or hold the CHANGE key to modify the number of gallons to be burned before the reminder.
When the value is properly set, tap STEP to save changes.
When REMINDER TIMEOUT=5 is displayed, you can tap or hold the CHANGE button to change the number of seconds that the reminder is displayed before being automatically dismissed.
Tap NEXT until END? is displayed.
Tap YES to restart the EDM.