120P3439X012
May 12, 2026

120P3439X012

atiThe 120P3439X012 is a high-performance industrial universal I/O module designed for industrial automation, process control systems and PLC expansion applicons. It integrates multi-channel analog and digital input and output functions in one compact DIN rail mounting housing. Adopting industrial-grade circuit design, isolated power supply and comprehensive protection circuit, this module features high-precision signal acquisition, strong anti-interference capability, stable long-term operation and wide temperature adaptability. It supports standard industrial current and voltage signals, adopts RS485 communication interface and complies with Modbus RTU protocol. It is widely applied in mechanical automation, water treatment, HVAC engineering, environmental monitoring and factory automatic control scenarios. Standard 35mm DIN rail installation ensures simple field installation, convenient wiring and easy daily maintenance.

Description

1. Product Overview

atiThe 120P3439X012 is a high-performance industrial universal I/O module designed for industrial automation, process control systems and PLC expansion applicons. It integrates multi-channel analog and digital input and output functions in one compact DIN rail mounting housing.
Adopting industrial-grade circuit design, isolated power supply and comprehensive protection circuit, this module features high-precision signal acquisition, strong anti-interference capability, stable long-term operation and wide temperature adaptability. It supports standard industrial current and voltage signals, adopts RS485 communication interface and complies with Modbus RTU protocol. It is widely applied in mechanical automation, water treatment, HVAC engineering, environmental monitoring and factory automatic control scenarios. Standard 35mm DIN rail installation ensures simple field installation, convenient wiring and easy daily maintenance.

2. Main Features

  • Integrated multi-channel hybrid input and output design, compact structure and high cost performance

  • 16-bit high precision ADC and DAC, ensuring accurate analog signal sampling and output

  • Full software configurable signal type, measurement range and working operation mode

  • Built-in isolation protection, overvoltage, overcurrent, short-circuit and overtemperature protection

  • Equipped with standard RS485 interface, supports Modbus RTU communication protocol

  • Wide operating temperature range, suitable for harsh industrial on-site environment

  • Digital channels support NPN/PNP logic selection and adjustable anti-shake debounce time

  • Analog channels support digital filtering algorithm and user-defined fail-safe output mode

  • Flame-retardant engineering plastic housing, low power consumption and high operation reliability

  • Support remote parameter configuration, real-time data reading and equipment status monitoring

3. Technical Specifications

3.1 General Parameters

Model: 120P3439X012
Rated Power Supply: 24 VDC ±10%
Maximum Working Current: 300 mA
Isolation Voltage: 1500 VDC isolation between field side and internal circuit
Operating Temperature: -25 ℃ ~ +60 ℃
Storage Temperature: -40 ℃ ~ +85 ℃
Relative Humidity: 5% ~ 95% RH, non-condensing
Mounting Method: Standard 35 mm DIN rail
Housing Material: Industrial flame-retardant plastic

3.2 Channel Resource Configuration

Analog Input: 4 channels, 4~20 mA / 0~10 V software selectable
Analog Output: 2 channels, 4~20 mA / 0~10 V software selectable
Digital Input: 8 channels, 24 VDC level compatible
Digital Output: 4 channels, single channel rated load 0.5 A

3.3 Analog Performance Parameters

Resolution: 16-bit
Basic Accuracy: ±0.1% Full Scale at ambient temperature
Temperature Drift: ±0.2% Full Scale within full temperature range
Analog Input Load: Current type ≤ 250 Ω; Voltage type ≥ 100 kΩ
Analog Output Load: Current type ≤ 500 Ω; Voltage type ≥ 1 kΩ

3.4 Communication Parameters

Communication Interface: RS485
Communication Protocol: Modbus RTU
Default Baud Rate: 9600 bps
Data Format: 8 data bits, 1 stop bit, no parity
Modbus Station Address: 1 ~ 247 configurable

4. Safety Precautions

  • Installation, wiring and maintenance work must be performed by qualified professional technicians.

  • Disconnect all power supply before wiring, disassembly or maintenance to avoid electric shock and equipment damage.

  • Do not install the module in areas with flammable gas, explosive dust, corrosive vapor or conductive particles.

  • Maintain sufficient ventilation clearance around the module; do not block heat dissipation slots.

  • Power cables and signal cables must be routed separately to reduce electromagnetic interference.

  • The protective grounding terminal must be connected to reliable earth ground to ensure safety and anti-interference performance.

  • Do not operate beyond the rated load range of each input and output channel.

  • Do not disassemble, modify or refit the internal structure of the module without authorization.

5. Installation and Terminal Definition

5.1 DIN Rail Installation Steps

  1. Fix the standard 35 mm DIN rail firmly on the mounting base.

  2. Align the upper mounting buckle of the module with the DIN rail edge.

  3. Press the module downward until the bottom locking buckle clicks into place.

  4. Slightly shake the module to confirm it is firmly fixed without sliding or loosening.

5.2 Terminal Pin Assignment

1     24VDC Power Positive
2     24VDC Power Negative
3     Analog Input 1 Positive
4     Analog Input 1 Negative
5     Analog Input 2 Positive
6     Analog Input 2 Negative
7     Analog Input 3 Positive
8     Analog Input 3 Negative
9     Analog Input 4 Positive
10    Analog Input 4 Negative
11    Analog Output 1 Positive
12    Analog Output 1 Negative
13    Analog Output 2 Positive
14    Analog Output 2 Negative
15    Digital Input Common
16    Digital Input Channel 1
17    Digital Input Channel 2
18    Digital Input Channel 3
19    Digital Input Channel 4
20    Digital Input Channel 5
21    Digital Input Channel 6
22    Digital Input Channel 7
23    Digital Input Channel 8
24    Digital Output Channel 1
25    Digital Output Channel 2
26    Digital Output Channel 3
27    Digital Output Channel 4
28    Digital Output Common
29    Protective Ground Terminal

5.3 Wiring Instructions

  1. Strip approximately 6 mm insulation layer from the wire end.

  2. Loosen terminal screws with a standard screwdriver.

  3. Insert wires into corresponding terminals strictly according to terminal definition.

  4. Tighten screws moderately to ensure reliable contact; avoid over-tightening damage.

  5. Use cable ties to fix wiring to prevent pulling stress on terminals.

  6. Analog signal wiring adopts shielded twisted-pair cable with single-end shield grounding.

  7. Digital signal uses stranded copper wire with appropriate wire gauge.

6. Parameter Configuration

6.1 Connection Method

Connect the RS485 interface of 120P3439X012 to a PC via USB-to-RS485 adapter. Run dedicated configuration software to scan and connect the module automatically.

6.2 Configurable Parameters

Analog Input

Signal type selection: 4~20 mA / 0~10 V
Custom engineering range setup
Digital filter enable and filter frequency adjustment

Analog Output

Signal type selection: 4~20 mA / 0~10 V
Output range calibration and matching
Fail-safe mode: fixed value or hold last value when communication is lost

Digital Input

Input logic mode configuration
Debounce time adjustable from 0 ms to 500 ms

Digital Output

Output logic mode selection
Fail-safe state setting: always ON or always OFF during communication failure
Pulse output mode and pulse width parameter configuration

Communication Setting

Optional baud rate: 9600 / 19200 / 38400 bps
Modbus station address modification
Support one-key restore factory default parameters

6.3 Save and Activation

After completing all parameter settings, save configuration data to the module. Power off and restart the module to activate all new parameters.

7. Operation Description

7.1 Power-on Self-test

After 24 VDC power is supplied, the power indicator lights up. The module completes internal self-diagnosis within 2 seconds. If no fault is detected, it automatically enters normal operation mode.

7.2 Working Mode

  • Analog Input: Collect analog signals from field sensors, convert into digital data and upload to upper control system in real time.

  • Analog Output: Receive control commands from the main controller and convert into standard analog signals to adjust valves, actuators and other execution devices.

  • Digital Input: Detect on-off status of switches, sensors and relays, and upload status changes in real time.

  • Digital Output: Turn on or off external relays, solenoid valves and indicator lights according to system control commands.

  • Communication: Realize data interaction, parameter reading and writing with upper controller through Modbus RTU protocol.

7.3 Indicator Status Description

Power LED Steady Green: Power supply normal
Power LED Off: No power or power supply fault
Status LED Green Flashing: Normal operation, no fault detected
Status LED Red Flashing: Overload, short circuit or communication abnormality
Status LED Steady Red: Severe hardware fault, module replacement required

8. Daily Maintenance

  • Regularly check indicator working status and terminal tightness; inspect for oxidation and loose contact.

  • Clean module surface only with dry soft cloth; do not use liquid or chemical solvents.

  • Ensure the operating environment temperature and humidity are within the specified range.

  • Periodically inspect aging of external cables and replace damaged wires in time.

  • When module performance is abnormal, replace with the same model and reconfigure parameters.

9. Troubleshooting

  1. Power indicator not lit
    Cause: No 24VDC input, power polarity reversed or wire broken
    Solution: Check power circuit and wiring polarity, restore normal power supply
  2. Status indicator red flashing
    Cause: Output overload, short circuit, self-test failure or communication interruption
    Solution: Disconnect field load, eliminate short circuit and overload, restart module power
  3. Analog input data abnormal
    Cause: Incorrect signal type setting, loose terminal or mismatched load resistance
    Solution: Reconfigure channel signal type, fasten terminals and match load parameters
  4. Analog output inaccurate
    Cause: Improper range setting, excessive load resistance or poor contact
    Solution: Reset engineering range, control load within rated specification
  5. Digital input no response
    Cause: Wrong logic configuration, loose wiring or sensor failure
    Solution: Adjust input logic parameters, check and fasten wiring
  6. Digital output cannot switch normally
    Cause: Overload current, incorrect logic mode or loose terminal
    Solution: Reduce load current to rated range, reconfigure logic and tighten terminals
  7. RS485 communication failure
    Cause: Mismatched baud rate or address, A/B signal line reversed, missing terminal resistance
    Solution: Unify communication parameters, correct A/B wiring, add matched terminal resistor

10. Warranty Terms

This module is covered by limited warranty against manufacturing and material defects. The warranty does not cover damage caused by improper installation, overload operation, unauthorized disassembly, modification or application beyond specified environmental conditions.


Get a Quote