Product Overview
When your production line demands precise control and rapid response, the Schneider TM258LF42DT delivers. This compact base logic controller from the Modicon M258 series integrates 42 discrete I/O points in a space-saving design. With a 24 V DC supply and built-in CANopen master, it simplifies machine automation while maintaining high performance.

Key Technical Specifications
The TM258LF42DT is engineered for speed and reliability. Here are the critical specs that matter for your application:
| Parameter | Value |
|———–|——-|
| Discrete I/O | 42 total |
| Discrete inputs | 10 fast, 12 standard, 4 regular |
| Discrete outputs | 12 standard, 4 fast |
| Input voltage | 24 V DC |
| Output voltage | 24 V DC (19.2…28.8 V) |
| Supply voltage | 24 V DC (20.4…28.8 V) |
| Execution time | 22 ns per Boolean instruction |
| Memory | Flash 128 MB, RAM 64 MB |
| Real-time clock | Drift ≤ 6 s/month (calibrated) |
| Communication | CANopen master, Ethernet Modbus TCP/IP, Modbus serial, USB |
| Mounting | Symmetrical DIN rail |
| Dimensions (W×H×D) | 175 × 99 × 85 mm |
| Weight | 0.55 kg |
| Ambient temperature | 0…55 °C (horizontal, no derating) |
| Protection | IP20 |
Industry Applications
This controller suits a wide range of automation tasks. In packaging machinery, the fast inputs (200 kHz counting) enable precise position tracking. For material handling systems, the CANopen master coordinates multiple drives and sensors. Its compact size fits into control cabinets with limited space, reducing installation costs.

Installation and Setup
Mount the TM258LF42DT on a standard DIN rail. Ensure proper clearance for ventilation and cable routing. Connect the 24 V DC supply within the specified limits (20.4…28.8 V). Use shielded cables for fast I/O to maintain signal integrity. The integrated CANopen port uses a SUB-D 9 connector; set the node address and baud rate via software.
Maintenance and Reliability
Regularly inspect the controller for dust accumulation and loose connections. The real-time clock battery (CR2477M) provides up to 1.5 years of data retention; replace it proactively to avoid losing retain variables. Operating within the temperature range ensures long-term reliability.
Compatibility and Integration
The TM258LF42DT integrates seamlessly into Modicon M258 ecosystems. It supports CANopen master for distributed I/O and drives. The Ethernet port enables Modbus TCP/IP for HMI and SCADA connectivity. Two serial links (RS232/RS485) allow legacy device integration. USB ports facilitate programming and data transfer.
Troubleshooting Common Issues
If the controller fails to communicate over CANopen, check the bus termination and baud rate settings. For input signal issues, verify that the voltage state 1 is ≥15 V and state 0 is ≤5 V. If the real-time clock drifts, recalibrate it in software. For persistent problems, consult the user manual.
Purchasing Advice
Before ordering, confirm your power supply meets the 24 V DC requirement. Verify the I/O configuration matches your needs. At SpareTechPLC, we offer genuine Schneider TM258LF42DT units with fast shipping. Contact us for availability and bulk pricing.