SET-POINT FUNCTION

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Set-Points perform a vital function in the engine environment. The Set-Point function works with drive outputs, which can be activated from 14 different signal sources. This is for the implementation of, for example, fan control, gearshift lights, idle assistance and all other small jobs around the engine and passenger bay. All functions can be combined in a logical fashion, and full polarity (higher than/lower than) selection is possible. Furthermore, The SET-POINT procedure can be used to switch between the TWO operating maps A/B. The SET-POINT outputs are SHARED with the injection outputs.

 

EXAMPLE : SWITCH #2 WHEN THE RPM IS GREATER THAN 6500.

RPM = Input
6500 = set point
#2 = Output
Greater than = Compare direction

 

THE INPUTS CAN BE:

  • Analogue voltage (AMP, Lambda, Temperature)
  • Frequency

 

THE INPUTS CAN ALSO BE COMPUTED ITEMS SUCH AS:

  • AFR (Air Fuel Ratio )
  • RPM
  • Frequency
  • Manifold pressure (AMP)
  • Temperature
  • Digital (ON/OFF from other set points)

 Computed items are normally expressed in engineering units like Celsius, AFR, BAR, Hz, where straight inputs are in volts and milliseconds. If an input specifies the output of another function, then the relationship must be specified.

 

RELATIONSHIPS ARE:

AND: Item #1 AND item#2 must be true before an output is produced

OR: Either item #1 OR item #2 will produce an output.

 

EXAMPLE : SWITCH #2 WHEN THE RPM IS GREATER THAN 3500.

AND When Temperature is less than 80°C

 

RPM = Input item #1
3500 = set point item #1
#2 = Output (Common output)
Greater than = Compare direction item #1
Temperature = Input item #2
Less Than = Compare direction item #2
80°C = Set point #2
AND = Relationship

 

In the above example the output is true when the engine is below 80 Degrees C and the RPM greater 3500. Thus a cold engine can’t exceed 3500RPM.

Of course, more than two set-points can be combined in various relationships.
Example: If this…. AND this…. OR this…. is true then…..

 

SINCE THE SET POINT OUTPUT IS DIGITAL (SWITCH) THE ACTION IT PERFORMS IS EITHER:

  • Limiting
  • Switching
  • Warning

 

TUNING DEVICES WHICH WILL DO SET-POINT CONTROL:
XMS4 Stand Alone Product Range
SMT8 Piggy-Back Unit
SMT8L Piggy-Back Unit

 

VISIT THE FOLLOWING LINKS FOR MORE INFORMATION ON SET-POINT CONTROL:
Product Manuals
Application Notes
FAQ’s