We build custom communication libraries for Siemens PLCs, enabling ISO-on-TCP, TCP, and UDP data exchange fully tailored to your application logic, data structures, network architecture, and security requirements.

With over 20 years of hands-on industrial automation experience, we are specialists in Siemens Open User Communication (OUC)—unlocking Siemens controllers to communicate seamlessly in multi-vendor, complex industrial environments worldwide.

Expertise Across Core T-Blocks

We engineer robust, reliable communication using Siemens’ fundamental T-blocks, ensuring error-free, production-grade integration.

TCON — Connection Establishment

We configure and establish ISO-on-TCP, TCP, and UDP connections, defining one device as Active (initiator) and the other as Passive (listener) for predictable, stable link setup.

TSEND — Data Transmission

We send structured data—from bits to complex frames—using controlled REQ-triggered logic, ensuring deterministic transmission and non-optimized data block access for full compatibility.

TRCV — Data Reception

We implement accurate, reliable data parsing with EN_R-enabled reception and exact data structure mapping, safeguarding data integrity across the entire exchange.

TDISCON — Connection Management

We design clean lifecycle control, allowing planned shutdowns and reconfiguration while maintaining stable communication during runtime.

The table below summarizes our core competency with the essential SIEMENS T-block functions:

Function Block	Role & Expertise	Key Implementation Insight
TCON	Connection Establishment: Expertly configure and establish TCP, ISO-on-TCP, and UDP connections between devices.	We meticulously define one partner as Active (initiates connection) and the other as Passive (listens on a defined port), ensuring reliable link setup.
TSEND	Data Transmission: Robustly send data over established connections, handling everything from single bits to complex data structures.	We ensure source data blocks have “Optimized block access” disabled and use a proper REQ signal trigger for controlled data sending.
TRCV	Data Reception: Reliably receive data streams, accurately mapping them into pre-defined data structures in the receiving controller.	We maintain data integrity by enabling the EN_R input and ensuring the receive data block matches the exact structure of the incoming data.
TDISCON	Connection Management: Gracefully terminate connections when needed, providing full control over the communication lifecycle.	We use this for planned shutdowns or reconfiguration, as connections are otherwise automatically maintained by the CPU.

Custom Protocol Solutions, Globally Delivered

Cross-Vendor Integration

We connect Siemens PLCs to virtually any Ethernet-enabled system—other PLC brands, PC-based software, HMIs, robots, barcode scanners, printers, and more.

Protocol Implementation

We implement and optimize TCP, ISO-on-TCP, and UDP based on your needs for speed, reliability, latency, and data structure.

Global, Multi-Site Experience

We support clients across industries and continents, delivering standardized communication architectures for IIoT, SCADA, MES, and Industry 4.0 ecosystems.

Practical, Proven Best Practices

Accurate Connection Setup

We configure partner settings, IP mapping, and connection IDs correctly—including “Unspecified” device connections—ensuring first-time success.

Correct Data Block Handling

We avoid common pitfalls by disabling Optimized Block Access on TSEND/TRCV data blocks for consistent byte-true memory alignment.

Lifecycle & Stability Engineering

We design robust logic for connection establishment, monitoring, reconnection, and termination—ensuring predictable, stable PLC-to-device communication.

Future-Ready Standards

Beyond T-blocks, we also develop custom OPC UA–based communication for clients requiring modern, vendor-independent industrial data exchange aligned with Industry 4.0.

Ready to build your communication solution?

We apply decades of deep, practical experience to craft a reliable, secure, and tailored communication library for your Siemens PLC application.