Idec Plc Fa2j Manual

The IDEC FA2J User Manual is a classic example of late-80s/early-90s industrial documentation. It is dense, logic-focused, and functionally comprehensive but lacks the visual polish and intuitive navigation of modern documentation. It serves as a competent reference for seasoned electricians but can be overwhelming for novice programmers due to its "wall of text" approach to instruction set explanations.

| Module | Description | |---------|-------------| | FA2J-E8X | 8 DC inputs | | FA2J-E8YR | 8 relay outputs | | FA2J-E8YT | 8 transistor outputs | | FA2J-E4X4YR | 4 inputs / 4 relay outputs |

The relay outputs on the FA2J are rated for 2A resistive, but the manual strongly advises using external fuses and flyback diodes for inductive loads (solenoids, contactors). Failure to do so welds the relay contacts shut. idec plc fa2j manual

For technicians keeping old machinery alive, this is the most valuable part of the document.

| Feature | Specification | |--------|----------------| | CPU Types | FA2J-CPUA (24V DC), FA2J-CPUB (100-240V AC) | | Program Capacity | 3.2k steps (EEPROM) | | I/O Points | Max 120 points (24 built-in + expansion) | | Instruction Set | Basic (27 types) + Advanced (43 types – e.g., MOV, CMP, INC) | | Execution Speed | 2.0 µs / basic instruction | | Timers/Counters | 128 timers (0.01–3276.7 sec), 128 counters (1–32767) | | Internal Relays | 512 points (M0–M511) | | Data Registers | 256 words (D0–D255) | The IDEC FA2J User Manual is a classic

The manual generally follows the standard progression of PLC documentation from that era.

Verdict: The organization is logical but rigid. There is very little "task-based" help; you must know what you are looking for to find it. Without the manual

The back of the FA2J programming manual contains a cheat sheet of special relays. For example:

Without the manual, you would never know these exist.

LD I0   (Start PB)
OR Q0   (Motor contactor)
ANI I1  (Stop PB)
OUT Q0  (Motor output)