OMRON

Main Functions

1. Digital Mixed‑type I/O Expansion It is a dedicated expansion unit for Omron CPM1A micro‑PLC CPU units. It provides 12‑point DC24V digital inputs and 8‑point relay outputs, delivering 20 extra I/O points in total. DC input terminals accept NPN/PNP sensor signals; relay‑contact outputs support both AC and DC external loads. The unit connects to CPM1A CPU via the dedicated expansion connector, and I/O addresses are automatically assigned by the PLC system without special software configuration. Up to 3 such expansion units can be connected to a 30‑point or 40‑point CPM1A CPU to increase overall system I/O capacity.plcva.com
2. Relay‑contact Output Characteristics Each relay output channel supports maximum 2 A resistive load. Relay contacts can switch AC‑type loads (e.g. solenoid valves, contactors) as well as DC loads. Compared with transistor outputs, relay outputs feature isolation between PLC internal circuit and field side, and tolerate higher‑voltage external actuators. Note that relay outputs are not suitable for high‑frequency rapid‑switching applications due to mechanical contact wear.
3. Input Circuit Performance DC input rated voltage: DC 24 V (20.4‑26.4 V operating range). Built‑in optical‑coupler isolation suppresses industrial‑site electrical noise. Each input and output channel is equipped with LED status indicators for on‑site visual diagnosis of signal status. It adopts DIN‑rail mounting structure with screw‑type terminal blocks for convenient field wiring.
4. Simple System Integration No programming or parameter setup is required for the hardware itself. After physical connection, the CPM1A CPU automatically recognizes the expansion unit. I/O status can be directly read‑written by ladder‑logic programs. This unit works with CX‑Programmer programming software for monitoring and debugging.
5. Product Status Notice CPM1A series has been discontinued since March 2015; CPM1A‑20EDR1 is an end‑of‑life legacy expansion module, widely used for spare‑part replacement of old‑generation automation equipment.

Omron CPM1A‑20EDR1

Applications / Purposes

1. I/O capacity expansion for CPM1A micro‑PLC systems Mainly used to expand digital input and output points for CPM1A‑series compact PLCs when the built‑in CPU I/O resources are insufficient. It increases total system I/O points without replacing the main CPU unit.
2. Control mixed‑voltage field actuators The relay‑contact output is ideal for driving AC‑powered solenoid valves, intermediate relays, indicator lamps, small contactors and other general‑purpose actuators. DC‑type proximity switches, photoelectric sensors, limit switches and push‑buttons are connected to DC input channels to collect field‑device status signals.
3. Small‑size standalone automation machinery Applied to low‑speed automation equipment such as simple assembly machines, small packaging machines, conveyor‑line auxiliary control, material‑sorting devices and test fixtures. Suited for scenarios that do not require high‑speed pulse output.
4. Legacy‑equipment maintenance & retrofitting Serves as spare‑part replacement for old production‑line control cabinets equipped with CPM1A‑series PLCs. It is widely used for maintenance‑related projects of existing factory automation systems.