GRT Avionics, Inc.
May 2019
Sport EX/Horizon EX Install. Manual
29
Rev. A
5-15: Basic Engine Monitoring Required Settings
When using the optional basic engine monitoring function, the following settings must be
made to allow for accurate readings to be made. These settings are accessed from the
“General Setup” submenu within the “Set” menu. They are located just below the serial
port settings.
TachP/R:
The TachP/R setting must be set to match the number of pulses per revolution
of the engine provided by the tachometer connection. The following table shows the most
common settings:
Pulses per
Revolution
Engine Type
Equivalent EIS Tach
P/R Setting
1.5
6-Cylinder, 4-Stroke with Magneto
0
1
4-Cylinder, 4-Stroke with Magneto
1
2
Rotax 2-Cycle
– Point-Style Ignition
2
5
Jabiru 4-Cylinder (S/N 22A2662 and Older) 5
6
Jabiru 4-Cylinder (S/N 22A2663 and
Newer)
6
6
Jabiru 6-Cylinder
6
6
Rotax 2-Cycle with CDI Ignition
6
6
Hirth
6
6
HKS
6
1.25
5-Cylinder, 4-Stroke with Magneto
17
1.75
7-Cylinder, 4-Stroke with Magneto
18
2.25
9-Cylinder, 4-Stroke with Magneto
19
Tachometer Sensitivity:
(Low/High)
The tachometer input includes a sensitivity
adjustment. The “Low” sensitivity setting is best for most tachometer connections as it
provides the greatest amount of filtering and tolerance of noise on the tachometer signal
from the engine. The “High” sensitivity setting is best for connections to electronic ignition
systems that provide a 0-5V pulse output. Since less filtering is provided when the high
sensitivity setting is used, it should not be used unless required.
*NOTE:
The tachometer input can tolerate signals of 200V or greater, regardless of the
TachSen setting.
**CAUTION:
Accurate tachometer readings should be verified by another tachometer
source, such as an optical tachometer. Attempting to fly with insufficient engine power
could be dangerous.
