When 28 Field Signals Outgrow a Compact PLC
A packaging line engineer faced a familiar problem: the TSX Micro PLC running the case sealer had run out of discrete points. Adding another controller meant new programming, new wiring, and downtime the production schedule could not absorb. The fix was a single module that expands the existing rack without touching the control logic. That module is the TSXDMZ28DT from Schneider Electric.
What the TSXDMZ28DT Delivers
The TSXDMZ28DT is a discrete solid state I/O base DC built for the Modicon TSX Micro automation platform. It combines 16 discrete inputs on a 1 HE-10 connector with 12 discrete outputs on a screw terminal block. The module runs on 24 V DC and draws 132 mA. Power dissipation stays at 3.5 W by module output and 0.15 W by channel output, with 5 W on the input side. That low thermal load matters in crowded cabinets where heat shortens the life of every component around it.
Key Parameters That Shape Real Performance
Input Thresholds and Sensor Compatibility
An input registers as state 1 at 11 V or higher and as state 0 below 5 V. Guaranteed current is 2.5 mA or more at state 1 and 1.5 mA or less at state 0. The module accepts 2-wire and 3-wire proximity sensors, so inductive and photoelectric devices connect without extra conditioning hardware.
Output Limits and Protection
Output voltage limits span 19 to 30 V, and output current limits cap at 0.625 A. Maximum leakage current is 0.5 mA at state 0, with residual voltage of 0.3 V. Output overvoltage protection uses a zener diode. Short-circuit protection comes from a current limiter and electronic circuit breaker. A reverse diode on the power supply handles reverse polarity. Outputs can be paralleled, two maximum.
Speed and Isolation
Output response time is 0.5 ms or less in both directions. Input response ranges from 0.1 to 7.5 ms. Isolation voltage is rated at 1500 V for 1 second. Switching frequency is below 0.6/LI² Hz. Load impedance is 48 Ohm.
Where This Module Fits
Replacement and upgrade path. A food processing plant running an aging TSX Micro rack can swap in the TSXDMZ28DT to restore full I/O count without redesigning the panel. The 24 V DC interface matches existing sensor and actuator wiring.
Material handling. Conveyor diverters need fast output switching. The 0.5 ms output response keeps sortation timing tight.
Process skids. With an operating temperature range of -20°C to 55°C and IEC 1131-2 Type 1 environmental compliance, the module suits skids that see temperature swings.
Installation Notes
Mount the module in the TSX Micro rack and secure the HE-10 connector for inputs. Wire outputs to the screw terminal block. Keep 24 V DC supply wiring separated from signal runs to reduce noise. Confirm input voltage stays above 11 V for active signals and below 5 V for inactive ones. The module measures 5.5 cm high, 18.0 cm wide, and 26.0 cm long, and weighs 0.425 kg.
Maintenance and Long-Term Value
Inspect terminal connections periodically for looseness. Check cabinet temperature stays within the rated range. Verify leakage current stays low if outputs drive sensitive loads. Because the module dissipates only 3.5 W by module output, it places minimal strain on cabinet cooling. That efficiency supports a lower total cost of ownership across the rack’s service life.
Compatibility Check Before You Buy
Confirm your rack belongs to the Modicon TSX Micro automation platform. Verify your sensors are 2-wire or 3-wire types. Check that load current stays under 0.625 A per output. SpareTechPLC supplies this module and can confirm current lifecycle status and availability before you order.
Frequently Asked Questions
Q: Can I parallel two outputs on the TSXDMZ28DT?
A: Yes. Paralleling is allowed with two outputs maximum.
Q: What sensors work with the inputs?
A: The module accepts 2-wire and 3-wire proximity sensors.
Q: How fast do outputs switch?
A: Output response time is 0.5 ms or less from state 0 to state 1 and from state 1 to state 0.
Q: What protects the outputs from faults?
A: A zener diode handles overvoltage, while a current limiter and electronic circuit breaker handle short circuits.
Q: What is the isolation rating?
A: Isolation voltage is 1500 V for 1 second.
