OMRON CQM1‑AD041 4‑Channel Analog Input Module for CQM1 PLC
The OMRON CQM1‑AD041 is a dedicated analog input slave module for the CQM1 series programmable logic controllers. It provides four independent analog input channels, each configurable for voltage (0‑10 V, 0‑5 V) or current (4‑20 mA) signals. With 12‑bit resolution (0‑4095 counts) and a fast conversion time of 2.5 ms per channel, this module enables accurate reading of process variables such as pressure, temperature, flow, and level.
Analog Input Specifications
Voltage range: 0‑10 V DC or 0‑5 V DC (selectable per channel via DIP switch). Input impedance: 1 MΩ. Current range: 4‑20 mA (input impedance 250 Ω). Conversion method: successive approximation. Resolution: 12 bits (2.44 mV for 0‑10 V, 1.22 mV for 0‑5 V, 4.88 μA for 4‑20 mA). Overall accuracy: ±0.5% of full scale at 25 °C, with temperature drift ±0.02%/°C. The module provides input filtering (1 kHz cutoff) and overvoltage protection up to 30 V. Open circuit detection is available for current loops: if the input drops below 1.5 mA, an error flag is set.
Data Format and Addressing
The CQM1‑AD041 occupies four input words in the PLC’s I/O memory (IR area), one per channel. Data is stored as binary values from 0 to 4095. Optionally, via DIP switch, the output can be configured as BCD 0‑2000 (0‑10 V) or 0‑1000 (0‑5 V) for direct display on numeric indicators. The module also provides a status word that indicates input overload, open circuit, or configuration errors. The unit number is set by a rotary switch (0‑9) on the front panel, determining the starting address.
Installation and Wiring
The CQM1‑AD041 mounts on the right side of any CQM1 CPU (CPU11, CPU21, CPU41, CPU44) as a standard expansion unit. It can be combined with up to 11 other expansion modules. The module requires an external 24 V DC power supply (100 mA typical), which can be provided by the CQM1‑IPS02 or an external source. Wiring uses a removable 10‑pin terminal block (M3 screws). For current loops, the external transmitter must be powered separately; the module does not provide loop power. Shielded twisted‑pair cable is recommended, with the shield connected to the module’s SH terminal.
Special Functions
The CQM1‑AD041 includes a moving average filter (2 to 64 samples) to smooth noisy signals, configurable via the software or DIP switch. It also offers peak and valley hold functions: the module can store the maximum and minimum input values since the last reset. These features are programmed by setting specific bits in the output word from the PLC. The module runs a self‑diagnosis at power‑up, checking A/D converter linearity and reference voltage.
Environmental and Compliance
Operating temperature: 0‑55 °C; storage: -20‑75 °C. Humidity: 35‑90% non‑condensing. Dimensions: 60 × 90 × 70 mm (H×W×D). Weight 150 g. The module complies with UL 508, CSA C22.2 No. 142, and EN 61131‑2. It carries CE marking for electromagnetic compatibility. Power consumption from backplane: 150 mA at 5 V DC.
Typical Applications
The CQM1‑AD041 is used in plastic injection moulding (pressure transducers), water treatment (pH sensors), food processing (temperature transmitters), and packaging (fill level sensors). Its four channels allow monitoring of multiple analog points without consuming many rack slots. When combined with an analog output module (CQM1‑DA021), it forms a compact PID control loop.
