D
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AXX
S
WITCHES
Overview:
Your
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system has the capability to monitor multiple switched on / off events. You can monitor
switches that connect to ground or 12 volts. There are two designated switch inputs and any of the rpm
channels can also be converted into switch inputs. If you are monitoring a solenoid or another “nasty”
signal, it is recommended to the optically isolated channels of Input shaft or Magneto.
Installation:
To install a non-powered switch with a common ground, simply connect the switch wire to the SW1 or
SW2 input. If not using a common ground connect the ground wire to the ground terminal near the
switch signal.
To install a switch that will monitor a 12V signal, you must first decide if it’s a “nice” or “nasty” signal.
Nasty signals produce high voltage spikes, such as solenoids, and can actually damage your
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if not installed properly. In order to protect the main module there are two optically isolated inputs, the
input shaft and magneto channel, both of which can be calibrated to be switch inputs. Any nasty signals
should use the optically isolated channel and nice signals can use either.
Warning: Both NHRA and IHRA frown upon attaching any electronic device to your trans brake
besides a delay box. Check with your local official before installing any trans brake switch. Also,
connecting a trans brake to an input that is not optically isolated will cause a power surge to your
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, possibly destroying it and voiding your warranty.
If you choose to monitor your trans brake, connect the trans brake signal wire to the magneto signal
(terminal id #42) and connect a separate ground to the magneto ground (terminal id #41). Place both
the Mag PuP (A) and Mag Gnd (B) dip switches to the OFF position in order to isolate the noisy trans
brake signal from the rest of the system. Finally change the magneto channel calibration to “Switch
(Ground is Off).
Calibration:
To configure, open the Calibration/Configuration window, and click on the “configure” button for the
specific channel that you have plugged the switch into. You can now choose either “Ground is On” or
“Ground is Off”.
Testing:
By default the LCD will show both switch 1 and 2. Changing the switch should change the display. If
you are not using an LCD then recording a log file should display the switches at the top of the screen
in zone one. If you are not getting any reaction from your switched input, test by touching a ground
input to the switch signal, a change should appear.
If you are trying to monitor a powered switch yet no change is apparent, it is most likely due to the fact
Copyright c 2008 Computech Systems Inc. 33