Siemens 6ES5526-3LB11 Communications Processor

High-Performance Communication for S5-135U/155U Systems

The Siemens 6ES5526-3LB11 communications processor manages data exchange between S5-135U/155U controllers and peripheral devices. This module handles complex protocol processing, offloading the CPU for better performance. Industrial networks with multiple communication devices benefit from this dedicated processing power.

Communication Specifications and Interface Options

This communications processor features two independent RS-232C/RS-485 ports for flexible device connectivity. Each port supports data rates from 300 bps to 38.4 kbps with software-selectable parameters. An integrated 16 KB dual-port RAM provides efficient data exchange with the host CPU. Furthermore, the module supports the 3964R, RK512, and ASCII protocols for versatile communication.

Parameter	Specification
Brand	Siemens
Model	6ES5526-3LB11
Number of Ports	2 (independent)
Interface Types	RS-232C, RS-485 (selectable)
Data Rates	300 bps to 38.4 kbps
Dual-Port RAM	16 KB
Protocols Supported	3964R, RK512, ASCII
Handshake	Hardware (RTS/CTS)
Dimensions (W x H x D)	50 mm x 125 mm x 118 mm
Weight	0.45 kg
Power Consumption	5 V DC at 350 mA
Compatible CPUs	S5-135U, S5-155U
Operating Temperature	0°C to 55°C

Data Handling and Flow Control

The Siemens 6ES5526-3LB11 utilizes hardware handshake lines for reliable data flow control on each port. The 16 KB dual-port RAM facilitates fast data exchange between the module and the CPU. Users can configure data bits, stop bits, and parity through the STEP 5 software. Additionally, the module supports both half-duplex and full-duplex communication modes.

Physical Design and Installation

This communications processor features a 50 mm housing that fits standard S5-135U and S5-155U rack slots. The unit weighs approximately 0.45 kilograms, allowing straightforward installation. Two 9-pin D-sub connectors on the front panel provide the serial interfaces. The module includes LED indicators for power and data transmission status on each port.

System Integration and Configuration

You can install this communications processor in any standard S5-135U or S5-155U rack slot. The module automatically maps to the CPU’s I/O address space for data access. Users configure communication parameters using the STEP 5 programming software. Moreover, the module supports custom protocol definition for specialized equipment integration.

Diagnostic Features and Status Monitoring

Front-panel LEDs indicate power, transmit activity, receive activity, and error conditions for each port. The module stores diagnostic information about communication errors in an internal buffer. A built-in loopback test verifies port functionality during system startup. Furthermore, the module supports remote diagnostics through the backplane bus.