Working Principle of Joystick Controller

Electromagnetic Chuck Controller

The 380V AC voltage is stepped down by a transformer, then rectified into 110V DC before entering the control unit and supplying the chuck. At this stage, the chuck becomes magnetized. For demagnetization, a reverse voltage is applied through the control circuit to achieve the demagnetization function.

Access Control Controller

The access control controller operates in two modes: Polling Mode and Recognition Mode.

• Polling Mode: The controller continuously sends query codes to the card reader and receives response commands. This mode persists until the card reader detects a card.

• Recognition Mode: Upon detecting a card, the reader sends a different response containing the card’s encoded data to the controller. The controller then verifies the card data against stored records and executes subsequent actions. After processing, the controller sends a reset command to the reader and reverts to Polling Mode.

Common Types of Joystick Controllers

Design Steps

1.  Instruction System Design: Define instruction types, quantities, formats, and functions.

2. Preliminary System Design: Register setup, bus arrangement, ALU design, and component interconnections.

3. Instruction Flowchart: Specify operations for each instruction, including timing and involved components.

4. Operation Timing Table: Break down instructions into micro-operations and schedule them by time segments.

5. Micro-operation Signal Logic: Derive and simplify control expressions, then implement them in circuitry.

Basic Components of Joystick Controller

1. Instruction Register (IR): Stores the current instruction, divided into opcode (operation type) and address field (operand location). Branch instructions modify execution flow by specifying a jump address.

2. Opcode Decoder: Interprets the opcode to generate corresponding control signals.

3. Timing Circuit: Produces synchronization signals (e.g., instruction cycle, bus cycle, clock cycle).

4. Micro-operation Generator: Executes control logic based on timing and opcode (e.g., "A→L" transfer). This is the most complex part of combinational logic controllers.

5. Program Counter (PC): Tracks the next instruction address. Normally increments by 1, but loads a jump address for branch instructions.

Microprogrammed Control

Proposed to overcome limitations of combinational logic (inflexibility, hard-to-modify designs), microprogramming stores control signals as firmware for easier updates and scalability.