Description
Reviews
| Brand | - |
| Category | Electronics & Electrical / PLC |
| Origin | - |
| Model Series | SR40, SR20, SR30, ST40, ST30, ST20 |
| Compatibility | Siemens S7-200 SMART Architecture |
| Input Voltage | AC 85-264V or DC 24V (Model Dependent) |
| Digital Inputs | 12 to 24 points depending on model |
| Digital Outputs | Relay or Transistor (Source/Sink) |
| Communication Ports | Integrated RS485 and Ethernet (PROFINET) |
| Programming Software | Compatible with STEP 7-Micro/WIN SMART |
| Mounting Type | Standard DIN Rail 35mm |
| Operating Temperature | -10°C to +55°C |
| Warranty Period | 12 Months Manufacturer Warranty |
Anonymous
Mar 29, 2026
Rating: 5/5
Fast shipping and good packaging
Ordered ten SR20 units for a client project. They arrived well-packaged and programmed easily. The terminal blocks are sturdy and easy to wire.
Anonymous
Mar 25, 2026
Rating: 5/5
Reliable and robust
Been running the SR30 in a dusty workshop environment for six months without a single glitch. The relay outputs handle our solenoid valves effortlessly.
Anonymous
Mar 25, 2026
Rating: 4/5
Solid performance for the price
These controllers offer about 80% of the premium brand features at half the cost. For non-critical applications, this is the smartest economic choice available.
Anonymous
Mar 25, 2026
Rating: 4/5
Great value for small automation projects
The ST20 model works perfectly for our packaging machine. Setup was quick using the standard software. Only giving 4 stars because the manual could be more detailed in English.
Anonymous
Mar 12, 2026
Rating: 5/5
Excellent communication features
The built-in Ethernet port on the ST40 makes HMI integration incredibly fast. We connected it to our SCADA system in under an hour. Highly recommended for modernizing plants.
Anonymous
Mar 11, 2026
Rating: 5/5
Perfect replacement for legacy systems
We used these SR40 units to upgrade an old production line. The compatibility with existing Siemens code was seamless, and the price point made it feasible to replace all controllers at once.
Q: Is there a battery required to retain the program?
A: No, these SMART PLCs utilize non-volatile memory (EEPROM) to retain your program and data permanently without the need for a backup battery.
Q: Can I use the original Siemens STEP 7-Micro/WIN SMART software to program these?
A: Yes, these PLCs are fully compatible with the standard STEP 7-Micro/WIN SMART programming environment, allowing you to use existing projects with minimal changes.
Q: Does the SR40 model support analog expansion modules?
A: Yes, the SR40 supports various analog expansion modules for temperature, voltage, and current signals, expanding its I/O capabilities significantly.
Q: Can I connect multiple PLCs via RS485 for Modbus communication?
A: Absolutely. The integrated RS485 port supports Modbus RTU protocol, allowing you to network multiple units as masters or slaves easily.
Q: What is the difference between the SR and ST series?
A: The 'SR' series features Relay outputs suitable for switching AC or DC loads, while the 'ST' series uses Transistor outputs designed for high-speed DC switching and pulse generation.
Anti-Tangle High-Strength Grade 100 Lifting Chain for Industrial Hoisting
$776.44
DIY Rose Essential Oil Handmade Soap Customization
$35.00
Adjustable Height Simple Storage Shelf - Wooden and Iron Bookcase, Steel-Wood Supermarket Display Rack
$256.00
DIY Handmade Soap Mold - Carnation Flower Rectangular Silicone Mold for Homemade Soap, Mother's Day Gift
$14.30
Fried Chicken Warmer Cabinet with Heat Lamp Small Single-Layer Insulated Box for Pies Youtiao Chestnuts and Roasted Sweet Potatoes Display Case
$500.00
Dried & Preserved Flower DIY Kit for Scented Candles – Ocean Style for Festivals, Team Building, and Workshops
$6.83
304 Stainless Steel Chain, Thickened Industrial Seamless Short/Long Link Chain for Lifting, Swing, or Dog Leash
$1.50
Large Bucket 502 Glue, Strong Instant Adhesive, Gold Material 502 Dry Glue for Leather, Metal, Furniture, and Plastic Bonding by Manufacturer
$1,893.00
Rectangular Plastic Vegetable Planter for Balcony - Durable Home Gardening Pot
$12.90
Chinese Painting Line Drawing Copybook, Gongbi Sketch Template, Large-Scale Tracing Album, Ancient Style Brush Control and Line Practice Book
$7.48
German Continental Tires 225/45R17 Run-Flat, 19-Inch Original Authentic with Full Tread Patterns
$380.00
Dynamic Sheet Music Simplified Notation Accompaniment for Electric Wind Instrument Saxophone Hulusi Ocarina Flute Bamboo Flute
$10.00
LL Industrial Lint-free Wiping Paper - Oil and Water Absorbent Non-woven Fabric (White/Blue Large Roll)
$185.82
Continental Quiet Used Car Tires 225/235/245/255/265-35/40/45/50 R17/18/19/20/21/22/23
$284.00
Negotiable Price: Siemens Load Cell 7mh4106-5ec11, Brand New Unused, Contact for Price Negotiation
$1,332.00
Premium Over-Toilet Storage Organizer, Wall-Mounted Bathroom Shelf, No Drilling Required, Multi-Function Toilet Rack
$31.76
Model 2000 Large Commercial Vegetable Cutter for Slicing, Dicing, and Cutting Leafy Greens and Kimchi
$11,000.00
Aromatherapy Candle Tool Set - Includes Igniter, Snuffer, Wick Trimmer, Flame Extinguisher Cover, and Rotating Carousel Ornament
$2.55
onlycook 304 Stainless Steel Kitchen Rack with Narrow Edge for Sink, Dishcloth Drainer, and Sponge Basket
$36.50
7-Piece Square Succulent Pot Set with Trays - Durable Plastic Colorful Root-Control Planters
$75.50
Minimalist Japanese Style Kitchen Sponge Brush Dish Soap Drain Rack Air-Dry Cloth Rack Sink Organizer Box
$21.00
PVC Cable Cover Speed Bump Style Wire Protector for Indoor Cables and Pipes
$9.10
Spiegel BGF-161 Portable Tire Stone Removal Hook - Multi-function Tool for Cleaning Car Tire Treads
$7.84
7A Natural Amethyst Purple Rabbit Hair Loose Beads for Women's DIY Bracelets and Snowflake Necklaces
$3.83
DIY Handmade Soap Silicone Mold, Essential Oil Soap, Creative Gift Soap Base and Aromatherapy Materials, Love Forever Design
$12.90
Flameless Aromatherapy Diffuser with Essential Oils, Dried Flowers, and Preserved Flower Decor
$13.60
DOUBLECOIN 7.00R16LT-14 (RSS2) All-Steel Radial Truck Tire - Economical and Wear-Resistant
$1,375.00
Tactical Laser Flashlight, Super Bright Rechargeable Mini Portable Light for Outdoor Long-Range Use, Home Multi-Function Zoom
$339.22
![MOOCAT [Polaroid Style] Hand-drawn Blank Irregular Wood Pulp Fine-grain Paper for Cyanotype, Street Vending, and Art Projects](https://www.gosteppe.com/cache/small/product/270441/legacy-main-3390792413846e9dfc410750.webp)
MOOCAT [Polaroid Style] Hand-drawn Blank Irregular Wood Pulp Fine-grain Paper for Cyanotype, Street Vending, and Art Projects
$11.90
New Pearl Mini Watercolor Solid Set – Portable Travel Sketchbook & Palette Kit for Students, 12 Colors with Magnetic Transparent Case
$5.78
![[Dangdang Machinery] German Imported Helukabel 4x2x0.25+2x1 Integrated Power and Network Cable 8+2](https://www.gosteppe.com/cache/medium/product/437884/legacy-main-19e2e1d822bc48ad489f93f5.webp)
