V3.57 Board Explanation:

The V357 is the base circuit board that the MS3 (or earlier versions) plug into, its main functions are:
Power supply
Basic engine sensor inputs
2 additional fuel channels (hi-z or low-z)
Fuel pump output
GM-style stepper idle control output
PWM idle output
Crank sensor input
RS232 serial interface
On-board 2.5 bar MAP sensor as standard (upgrades available)

MS3 Board Explanation:

The MS3 card is a plug-in processor board.
CPU - the heart of the ECU
SD card adapter
USB serial interface
Connection to mainboard
Connectors for MS3X

MS3X Board Explanation:

The MS3X card is an input/output board for the MS3
8 injector drivers (high-z or low-z with external resistors)
8 logic level spark outputs
6 mid current outputs for driving small solenoids or relays (on/off or PWM)
3 analogue inputs (0-5V)
4 switch inputs
Cam sensor input

MS3X or no MS3X?

The MS3 + mainboard package will give you batch fire fuel and DIY options for spark outputs.
A base MS3 ECU like this gives you an enhanced featureset over the MS2 ECU with SD card datalogging and built in USB serial. The MS3X can be added as a later upgrade.

The MS3 + MS3X + mainboard package right away gives you the eight sequential injector outputs, logic spark outputs, mid current outputs and the additional inputs. This gives the user access to the features without needing to DIY inside the box and provides for a standardised wiring system.

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