Omron CPM2B Board PLC Practical Guide

Omron CPM2B Board PLC Practical Guide

Product positioning and core features

Omron CPM2B is a board type PLC designed specifically for embedded control equipment, with a compact body size that can be directly installed inside the machine. Its biggest advantage is that the CPU board itself has integrated up to 40 I/O points, and the total number of points can be increased to 168 by expanding the I/O board. This series offers two power versions, 24V DC and 12V DC, with output types divided into relay and sinking transistor.

List of key functions:

High speed counter: 1 channel, differential phase mode 5kHz, pulse+direction, increase/decrease pulse or increment mode up to 20kHz

Interrupt input: 4-channel (multiplexed with high-speed counter input), minimum pulse width of 50 μ s, supports interrupt program execution

Pulse output: The transistor output model provides 2 single-phase 10Hz~10kHz pulses (adjustable duty cycle output), or 1 pulse with trapezoidal acceleration and deceleration+directional output

Synchronous pulse control: Input frequency 10~500Hz/20Hz~1kHz/300Hz~20kHz, output frequency 10Hz~10kHz

Analog Control: Built in two analog potentiometers (0~200 BCD), can connect up to 3 analog I/O boards (total 8 inputs and 4 outputs)

Communication function: peripheral port (programmer/upper computer connection), RS-232C port (supports Host Link, no protocol, 1:1 PLC Link, NT Link)

Clock and Battery: Built in calendar clock with a battery life of approximately 5 years (25 ℃)

These features make CPM2B very suitable for small and medium-sized devices that require precise positioning, speed synchronization, and data acquisition, such as packaging machines, labeling machines, and simple CNC workbenches.

Key points for system configuration and selection

2.1 Selection of CPU board model

CPM2B CPU board is distinguished by I/O points, power supply voltage, and output type:

Model Power Input Point Output Point Output Type Built in Features

CPM2B-32C1DR-D 24V DC 16 16 relay without clock/RS-232

CPM2B-32C2DR-D 24V DC 16 16 relay with clock/RS-232/battery

CPM2B-32C1DT-D 24V DC 16 16 transistor (sinking) no clock/RS-232

CPM2B-32C2DT-D 24V DC 16 16 transistor (sinking) with clock/RS-232/battery

CPM2B-40C2DR-D 24V DC 24 16 relay with clock/RS-232/battery

CPM2B-32C1DT1-D12 12V DC 16 16 transistor (sink) no clock/RS-232

CPM2B-32C2DT1-D12 12V DC 16 16 transistor (sink) with clock/RS-32/battery

Selection Tips:

If pulse output, high-speed counter or synchronous control are required, the transistor output model must be selected (relay output cannot output high-speed pulses).

Only models with clocks have batteries (C500-BAT08) to maintain DM/HR/AR zones and counter values. The clock free model relies on capacitors to hold for about 5 days.

The RS-232C port is only available on models with clocks. If you need to connect to an upper computer or PT, it is recommended to choose a model with RS-232C.

2.2 Expansion of I/O board

The CPU board can connect up to 3 expansion I/O boards (or up to 2 if using a 64 point board). Available models:

Model input/output connection method

CPM2B-32EDR 16 × 24V DC 16 relay terminal block

CPM2B-32EDT 16 × 24V DC 16 transistor (sinking) connector

CPM2B-32ED1T 16 × 12V DC 16 transistor (sinking) connector

CPM2B-40EDR 24 × 24V DC 16 relay terminal block

CPM2B-64EDT 32 × 24V DC 32 transistor (sinking) connector

I/O word allocation order: The CPU board itself occupies IR000~IR001 (input) and IR010~IR011 (output). The expansion board allocates subsequent input/output words in order of connection. The 32 point board accounts for 1 in and 1 out, while the 40/64 point board accounts for 2 in and 2 out. Please note that the total input words cannot exceed IR009, and the total output words cannot exceed IR019.

2.3 Analog I/O board

Only CPU boards with 24V DC power supply can be connected to analog boards. Up to 3 blocks, with a total input of no more than 8 channels and a total output of no more than 4 channels.

Model input point number output point number allocation

CPM2B-MAD21 2 1 Input 2 Words, Output 1 Word

CPM2B-MAD42 4 2 Input 4 Words, Output 2 Words

CPM2B-MAD63 6 3 Input 6 Words, Output 3 Words

Input/output signal range: 0~5V, 1~5V, 0~10V, -10~10V, 0~20mA, 4~20mA optional, resolution 1/6000 (full range). When using current input (4~20mA) or voltage input 1~5V, it has a disconnection detection function - when the input voltage is below 0.8V or the current is below 3.2mA, the converted data becomes 8000 (hexadecimal), and the disconnection is automatically cleared after recovery.

Important: The analog board needs to write a range code in the program to initiate A/D or D/A conversion. The range code is a 3-digit binary (000-100), which is written into the lower 3 bits of the corresponding output word (for example, bit00-02 of channel n+1 is used for analog input 1, bit06-08 is used for analog output 1, etc.). After power on, the first conversion of data takes about 50ms to stabilize, and a timer should be used in the program to delay reading.

Installation and wiring specifications

3.1 Installation Environment

CPM2B can only be installed inside the control cabinet and must meet the following requirements: