TM238LDD24DT Modicon M238 Controller 24 I/O High-Speed Positioning

TM238LDD24DT – Modicon M238 Compact Logic Controller

Base unit · 24 I/O · 24V DC supply · 500 kB RAM – Designed for small to medium high-speed control applications.

Technical Positioning

• 8 fast inputs (100 kHz) + 6 standard inputs, compliant with EN/IEC 61131-2 Type 1.
• 4 fast outputs (PTO/PWM up to 100 kHz) + 6 standard transistor outputs, sink/source configurable.
• Onboard 500 kB RAM, retain variables backed by optional lithium battery (1 year) or internal capacitor (3 days 22 hrs).
• Dual communication: isolated RS232/RS485 (Modbus RTU/ASCII) + USB 2.0 programming port.
• Expandable up to 7 I/O modules, total 248 I/O points (HE-10 connector).

Core Performance Data

• Input frequency : 100 kHz (normal/counter/fast) · response time 300 ns (fast input)
• Output frequency : 100 kHz (PTO) / 20 kHz (PWM) · load current 20…500 mA
• Instruction speed : 0.971 µs (Boolean) · 7.25 µs (floating point) · 0.42 µs (INT word)
• Isolation voltage : channel-to-logic 500 Vdc · I/O-to-ground 500 Vac (1 min)
• Power supply : 24 Vdc (19.2…28.8 V) · inrush ≤35 A · consumption ≤17.2 W
• Real-time clock : ±10 s/month at 25 °C · supports event/PID/high-speed counting

Installation · Debug · Maintenance

• Mounting: 35 mm symmetrical DIN rail or panel mount (4 screws).
• Wiring: removable screw terminal blocks (power/inputs/outputs/fast I/O separated).
• Debug interface: Mini USB 2.0 direct connection to SoMachine / EcoStruxure Machine Expert.
• Diagnostic LEDs: PWR, RUN, ERR, BAT, channel status, and SL1 serial indicator.
• Filter config: fast input 0.004 ms ~ 4 ms selectable; debounce 0~12 ms adjustable.

Environmental & Certifications

• Operating temperature : -10…55 °C · storage : -40…70 °C · humidity 95% non-condensing.
• Vibration resistance : 1 gn (3.5 mm, 5~150 Hz) · shock : 15 gn / 11 ms.
• Protection rating IP20 · pollution degree ≤2 · altitude 0~2000 m.
• Certifications : CSA, UL, CTick, GOST, CE marked.

Typical Applications & Compatible Equipment

• Suitable for: packaging machines, electronics assembly, small material handling, pump/fan speed control, lighting automation.
• Positioning: 2 independent 100 kHz PTO channels with 8 high-speed counters for precise motion.
• PWM dimming/speed: 2 channels 20 kHz PWM, duty cycle 20~80% accuracy ±1%.
• Expansion compatible: works with Modicon M218/M241 extension modules, supports HE-10/spring/screw terminals.

Oiltech Controls Insight

• ◈ Selection guide : If analog I/O or more relay outputs are needed, consider M241 or M251. M238 excels in pure digital applications with high-speed counting and PTO demands.
• ◈ Common pitfall : Fast outputs (PTO/PWM) drive only 100 mA max. Use interposing relays or amplifiers for high-power loads.
• ◈ Noise immunity : High-speed signal lines (counter/PTO) must use shielded cables, length ≤10 m (PWM/PTO mode) to ensure signal integrity.
• ◈ Memory planning : 500 kB RAM supports 3000~5000 steps. For heavy floating-point math, distribute tasks across auxiliary tasks.

Why Buy From Oiltech Controls?

• 15+ years in industrial automation spare parts – precise match for obsolete and active models.
• Global express shipping: FedEx / UPS / DHL – dispatch within 24~28 hours.
• Each unit functionally tested and firmware-verified; surplus/refurbished options available.
• 12-month warranty – covers manufacturing defects and early failures.
• Pre-shipment technical verification including I/O check, communication test, and load simulation.
• Specialized support for legacy control systems (Quantum, Premium) replacement solutions.

Package Contents & Logistics

• Includes: main unit ×1, power terminal block ×1, input terminal blocks ×2, output terminal blocks ×2, fast I/O terminal blocks ×2, DIN rail clip ×1, quick start guide (digital).
• Dispatch time: 24~28 hours (in-stock items), holidays may extend.
• Carriers: FedEx Priority, UPS Express, DHL International – tracking number provided.

Professional FAQ – Experience & Buying Guidance

• Q1: What is the main difference between TM238LDD24DT and the TM218 series?
  A: M238 offers 8 high-speed counters and 4 PTO channels (all 100 kHz), while M218 has only 4 fast inputs and 4 fast outputs. M238 is better for multi-axis basic positioning and high-speed counting.
• Q2: Can the fast output (PTO) directly drive a stepper driver?
  A: Yes, but ensure output current ≤100 mA (PTO mode). Add a 1~2 kΩ series resistor or opto-isolator, and keep shielded cable length ≤10 m.
• Q3: Is the program capacity sufficient for PID and floating-point calculations?
  A: Yes. Floating-point operations take ~7.25 µs each. 500 kB RAM can hold medium-sized programs (~2000 steps) including PID, but assign high-speed tasks to auxiliary tasks.
• Q4: How to choose expansion modules – screw or spring terminals?
  A: Spring terminals resist vibration; screw terminals ease frequent wiring. Max I/O count varies: HE-10 248 points, screw 136 points, spring 192 points.
• Q5: Is the lithium battery (TSXPLP01) mandatory?
  A: Not mandatory. Internal supercapacitor retains variables for 3 days 22 hours. For longer retention (>3 days) or persistent RTC, add the battery (1 year retention).