TM3DQ16T Overview
The TM3DQ16T from Schneider Electric is a discrete output module belonging to the Modicon TM3 family. It provides 16 transistor outputs with PNP (source) logic, designed for use with Modicon M221, M241, M251, and M262 controllers. This module delivers reliable switching for a wide range of industrial automation applications, offering a compact and cost-effective solution for controlling actuators, indicators, and other 24 V DC loads.

Key Technical Specifications
| Parameter | Value |
|————|——-|
| Output type | Transistor (PNP, source) |
| Number of outputs | 16 |
| Output voltage | 24 V DC |
| Output current | 500 mA per output |
| Response time | 450 µs turn-on / 450 µs turn-off |
| Maximum leakage current | 0.1 mA |
| Maximum voltage drop | <0.4 V |
| Maximum tungsten load | <3 W |
| Current consumption (bus) | 5 mA at 5 V DC (off), 15 mA at 5 V DC (on) |
| Current consumption (24 V) | 0 mA at 24 V DC (off), 20 mA at 24 V DC (on) |
| Local signalling | 1 green LED per channel |
| Electrical connection | Removable screw terminal block, 10 x 1.5 mm², pitch 3.81 mm |
| Insulation | Non-insulated between outputs |
| Mounting | TH35-15 or TH35-7.5 rail, or panel with fixing kit |
| Dimensions (H x D x W) | 90 mm x 84.6 mm x 27.4 mm |
| Net weight | 0.11 kg |
| Ambient temperature (operation) | -10…35 °C vertical, -10…55 °C horizontal |
| Ambient temperature (storage) | -25…70 °C |
| Relative humidity | 10…95% without condensation |
| IP degree | IP20 with protective cover |
| Pollution degree | 2 |
| Operating altitude | 0…2000 m |
| Standards | IEC 61131-2 |
| Product certifications | cULus, CE, UKCA, RCM, EAC, cULus HazLoc |
Industry Applications
The TM3DQ16T is ideal for applications requiring multiple 24 V DC outputs. Typical uses include:
- Packaging machinery: Controlling pneumatic valves and solenoid actuators.
- Material handling: Switching conveyor belt contactors and indicator lamps.
- HVAC systems: Managing damper actuators and fan starters.
Thanks to its fast 450 µs response time, the module is well suited for high-speed sequencing and precise timing control.

Installation and Setup
Mount the TM3DQ16T on a standard DIN rail (TH35-15 or TH35-7.5) or on a panel using the optional fixing kit. Ensure proper spacing for ventilation and maintain the specified operating temperature range. Connect outputs using the removable screw terminal block with a pitch of 3.81 mm, accepting wires up to 1.5 mm². For unshielded cables, keep the distance to loads under 30 meters to avoid voltage drops and interference. Always verify the wiring against the module’s labeling before powering up.
Maintenance and Reliability
The TM3DQ16T is built to withstand harsh industrial environments. It resists electrostatic discharge up to 8 kV in air and 4 kV on contact, and it tolerates vibration up to 3 gn at 8.4–150 Hz on DIN rail. To ensure long-term reliability:
- Inspect terminal connections periodically for tightness.
- Keep the protective cover in place to maintain IP20 rating.
- Avoid operating in condensing humidity.
With no moving parts, transistor outputs offer a longer service life than relay outputs, reducing downtime and maintenance costs.
Compatibility and Integration
The TM3DQ16T is compatible with Modicon M221, M241, M251, and M262 controllers. It connects via the TM3 bus, drawing power from the bus connector. The module supports positive logic (source) outputs, which are common in modern PLC systems. For mixed I/O requirements, combine with other TM3 modules in the same rack.
Buying Guide
When ordering the TM3DQ16T, verify your controller model and the required number of outputs. Ensure your power supply can handle the total output current (up to 500 mA per channel). The module comes with a screw terminal block; if you prefer spring terminals, consider alternative versions. SpareTechPLC stocks the TM3DQ16T and offers competitive pricing and fast delivery. Contact our team to confirm availability and lead times before placing your order.
Troubleshooting and Common Issues
- Output does not turn on: Check the output voltage (24 V DC) and the logic level. Ensure the load is within the 500 mA rating.
- Output turns on but load does not operate: Verify the wiring and the common connection. Check for voltage drop exceeding 0.4 V.
- LED is off but output is active: Confirm the LED is not faulty; measure the output voltage directly.
- Module not communicating with PLC: Verify the bus connection and that the module is properly seated.
For persistent issues, consult the Schneider Electric user manual for the Modicon TM3 system.