IMC CANSAS - Page 325

IGN ignition angle measurement module 325
imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
Camshaft pattern (degrees after top dead center)
If monitoring of selected cylinders is activated and the camshaft sensor is connected, the position at
which the camshaft sensor returns pulses is entered here. Die The pulses' angle-positions are
expressed in crankshaft degrees after the first cylinder's top dead center. The value range is typically 0
.. 720 degrees, thus encompassing one complete duty cycle or a full revolution of the camshaft.
Angles can also be expressed as negative values if they refer to positions before the first cylinder's top
dead center. The value range is from -720 to +720 degrees. All angle positions must be stated in
increasing order. In order for the pattern to be uniquely identifiable, the distances between the values
must be different, which also is always the case with a real camshaft. The individual angle positions
can be separated from each other by spaces or semicolons.
The camshaft pattern is specified by stating a trigger signal edge's angle positions. The channel
Camshaft's parameter Trigger signal edge (see channel parameters) defines which is the applicable
signal edge. If the positive edge is specified, the camshaft pattern must contain the angle positions of
all positive edges.
Thus, entering -45 degrees is equivalent to entering 675 degrees.
If the camshaft measurement wheel is not used, but a separate sensor is installed instead which
returns only one pulse per revolution of the camshaft, its angle position is stated, e.g. 30 for 30
degrees after the first cylinder's top dead center (TDC).
The following example shows a typical signal plot. The 4-stroke engine's duty cycle extends from 0 to
720° of the crankshaft. The preceding duty cycle goes from -720 to 0 degrees. What is shown are
ignition pulses at 30 degrees before TDC. The crankshaft's zero-marker is at 40 degrees before TDC
("40" is entered for the parameter Zero-marker on crankshaft [degrees before TDC]).