Siemens 6GK7542-1AX10-0XE0 PROFIBUS Communication Module for S7-1500
The Siemens 6GK7542-1AX10-0XE0 (also referenced as 6GK7 542-1AX10-0XE0) is a communication processor (CM 1542-5) for the SIMATIC S7-1500 PLC family. This module provides a high-performance PROFIBUS DP interface, allowing the S7-1500 controller to act as a PROFIBUS DP master or DP slave, or to connect to PROFIBUS FDL networks. It is part of the TIA Portal (Totally Integrated Automation) ecosystem, enabling seamless data exchange with drives, HMIs, and third-party devices.
PROFIBUS DP Master and Slave Modes
The CM 1542-5 supports both DP master class 1 and DP slave operation. As a DP master, it can control up to 124 DP slaves with a maximum cycle time of 8 ms (at 12 Mbit/s). The module automatically handles parameterization, configuration, and data exchange (cyclic I/O). In DP slave mode, the module responds to a higher-level DP master, making the S7-1500 appear as an intelligent slave. Switching between master and slave is done through parameter assignment in TIA Portal hardware configuration.
Transmission Rate and Connectors
Data rates from 9.6 kbit/s up to 12 Mbit/s are supported, with automatic detection in slave mode. The module uses a 5-pin terminal block (included) for PROFIBUS connection: pin A (green) for RxD/TxD-P, pin B (red) for RxD/TxD-N, and a shield terminal. An integral 150-ohm terminating resistor can be activated via a switch on the module, eliminating external terminators. For higher reliability, a PROFIBUS bus connector (e.g., 6ES7972-0BA12-0XA0) can be used.
Communication Protocols and Services
Beyond cyclic DP exchanges, the module supports a wide range of PROFIBUS protocols: S7 communication (server and client), PG/OP channel for programming and operator panels, FDL (Fieldbus Data Link) for peer-to-peer messaging, and SNMP for network diagnostics. It also supports PROFIsafe over PROFIBUS when combined with a safety-related CPU. The module stores up to 16 simultaneous S7 connections and 32 FDL connections. Data records up to 240 bytes per message are possible.
Integration with TIA Portal and STEP 7
Configuration is fully integrated into TIA Portal (V13 SP1 or later) and STEP 7 Professional. Drag-and-drop assignment of PROFIBUS addresses, GSD file management, and detailed diagnostics are available. The module supports “shared device” functionality, allowing one DP slave to exchange data with two DP masters. Real-time diagnostics are provided via the “PROFIBUS diagnosis” service, accessible from the CPU’s diagnostic buffer or via HMI.
Technical Data
Supply voltage: 24 VDC (20.4–28.8 VDC) via backplane or external terminal; current consumption 150 mA.
Power loss: Typical 3.6 W.
Isolation: 1500 VAC between PROFIBUS interface and CPU/backplane.
Memory: 8 MB buffer for message retransmission.
Operating temperature: 0 to 60°C; storage -40 to 70°C.
Dimensions (W x H x D): 35 mm x 147 mm x 129 mm.
Diagnostics and LEDs
Four status LEDs: PWR (green, power supply), RUN (green, module operational), ERROR (red, fault), and BUS (green, PROFIBUS active). The module logs bus errors, station failures, and parameter mismatches in an internal error stack (last 20 events). Online diagnostics can be triggered via the “Module state” web server page of the S7-1500 CPU. The module also supports time stamping of telegrams with 1 ms resolution.
Redundancy and Clock Synchronization
For high-availability applications, the module can be used in a media redundancy configuration (MRP) when paired with a PROFIBUS switch that supports redundancy. It also supports the “Isochronous Mode” for equidistant DP cycles, enabling precise axis synchronization (e.g., with SINAMICS drives). The module can synchronize its internal clock to the CPU’s real-time clock, logging events with consistent timestamps across the network.
Typical Applications
Typical installations include production lines, conveyor systems, printing presses, and process cells where PROFIBUS legacy devices are still prevalent. The CM 1542-5 replaces older CP 342-5 modules, offering higher performance and deeper integration with S7-1500 technology objects. It is also ideal for connecting distributed I/O ET 200 stations, valve terminals, barcode readers, and motor starters.
Installation and Cable Lengths
Maximum cable length per segment depends on baud rate: at 12 Mbit/s, 100 meters; at 1.5 Mbit/s, 200 meters; at 93.75 kbit/s, 1200 meters. Up to 9 segments with repeaters can extend to 9.6 km. The module automatically adjusts the bit timing based on the network parameters. Use of twisted-pair shielded cable (Siemens 6XV1830-0EH10) is recommended. When terminating the bus, ensure only the end devices have termination resistors enabled.
Ordering and Standards
Order number: 6GK7542-1AX10-0XE0. The module is certified for PROFIBUS International (PI) conformance, CE, UL 61010-2-201, and ATEX Zone 2 (non-incendive). It complies with RoHS directive 2011/65/EU. The firmware can be updated via TIA Portal without removing the module from the rack. A detailed product manual is available as article number 109754764 on the Siemens support portal.
