1. General Specifications
Parameter Specification
Product Name S7-200 SMART SR20 Communication Module
Order Number 6ES7 288-1SR20-0AA0
Module Type Point-to-Point Communication
Compatible CPUs All S7-200 SMART CPUs
Interface Type RS485/RS232 (switchable)
2. Communication Specifications
Parameter Specification
Transmission Rate 300 - 115,200 bps
Data Bits 7 or 8
Stop Bits 1 or 2
Parity None/Odd/Even
Protocol Support Freeport, Modbus RTU, USS
Cable Length RS485: Max. 1,200m
RS232: Max. 15m
3. Electrical Specifications
Parameter Specification
RS485 Signal Level ±12V
RS232 Signal Level ±12V
Connector Type 9-pin D-sub female
Isolation Voltage 500V AC
4. Mechanical Specifications
Parameter Specification
Dimensions (W×H×D) 45 × 100 × 75 mm
Weight 180g
Installation Right-side CPU expansion
5. Environmental Conditions
Parameter Specification
Operating Temperature 0°C to +55°C
Storage Temperature -40°C to +70°C
Relative Humidity 5% to 95% (non-condensing)
6. Software Configuration
Parameter Specification
Programming Software STEP 7-Micro/WIN SMART
Configuration Hardware configuration in system block
Diagnostics LED status indicators
7. LED Indicators
LED Function
RUN Module status
RX Receiving data
TX Transmitting data
8. Certifications
Standard Compliance
CE Yes
UL Yes
cULus Yes
RoHS Compliant
9. Typical Applications
Connection to barcode readers

Communication with weigh scales

Modbus RTU master/slave applications

Drive control via USS protocol

Legacy device connectivity

10. Ordering Information
Complete designation: 6ES7 288-1SR20-0AA0

Package includes: Communication module, documentation