Razor PDM Glossary of terms

ADIO

“Analog/Digital Input/Output”, the ADIO pins on the Razor PDM can be used as either an Analogue (detecting a range of voltages), or Digital (detecting if it has any voltage or not) input, or as a battery voltage output (Limited to 8amp continuous).

CAN

“Controller Area Network” is a central networking system that allows communication between devices in the vehicle, such as between a CAN keypad and the ECU, or ECU to PDM etc.

ECU

“Engine Control Unit” is computer that manages engine functions like fuel injection and ignition timing, based on sensor data. It monitors engine performance for diagnostics and safeties, and communicates with other units such as PDM’s, either controlling them directly, or using them as an IO expander.

High-side

In electronics, "high-side" refers to the position of a switch or load in relation to the power supply voltage. Specifically, a high-side switch is connected between the power supply (positive voltage) and the load.
If a Razor PDM has an input/output pin set as “high-side”, that pin is outputting battery voltage.

IO

Also “I/O”, stands for “Input/Output”. In the context of an ECU or PDM, pins labeled as "I/O" serve a dual purpose. They can function either as an input, receiving data from a sensor – or as an output, controlling components such as a solenoid or providing battery voltage to other devices.

Low-side

In electronics, "low-side" refers to the position of a switch or load relative to the ground (negative terminal) of a power supply. Specifically, a low-side switch is connected between the load and ground.
If a Razor PDM has an output pin set as “low-side”, that pin is allowing full load to ground through the PDM
If a Razor PDM has an input pin set as “low-side”, it will be using a software configurable pull-up resistor to detect when the pin is switched-to-ground.

PDM

“Power Distribution Module”, A solid state fuse and relay box replacement. PDMs simplify the design and maintenance of electrical systems, making them more efficient and reliable. Razor PDM’s can also work as IO expanders when CAN connected to a Link ECU.

Pull-up Resistor 

In the Razor PDM, an ADIO pin can be set as an input, software controlled pull-up resistors are used for detecting when that pin is being switched to ground. The resistor is preventing a full power short to ground when the circuit is closed, and allowing the PDM to detect when the circuit is closed. They are also required to be used with resistance based sensors such as temperature sensors.

PWM

“Pulse Width Modulation” is a technique used to control the power delivered to electrical devices by varying the width of the pulses in a pulse train. In practical terms, PWM allows you to adjust the effective voltage and current delivered to a device without changing the actual voltage level directly. For instance, in motor speed control, PWM can adjust the speed by changing the width of the pulses, effectively controlling how much power the motor receives over time.

Relay

Relay can mean either a physical relay, or a solid state relay. Both types of relay allow you trigger a high power circuit, by using a low power signal, and are used to isolate switches from the full power required to run whatever you are switching on and off.
A physical relay is an electrically operated physical switch that uses an electromagnet to control the opening and closing of another circuit.
A solid state relay performs the same function of a physical relay, but has no moving parts, using other electronic components to perform the switching.