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.
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