PN1-S25-TB Evaluation Kit: Quick Start Guide for Modbus to Profinet Integration

 

1. Product Positioning & Core Functions

The PN1-S25-TB is a specialized development and testing carrier board designed for the PN1-S25 Profinet Gateway Module. Its primary function is to facilitate bi-directional data conversion between Profinet Industrial Ethernet and Modbus RTU Serial protocols.

As a comprehensive evaluation tool, the kit breaks out all LED indicators, functional pins, and reset pins from the core module, eliminating the need for complex soldering. With integrated dual RS485 ports and a standard RJ45 Ethernet jack, it allows engineers to build a hardware test environment using only standard cables.

2. Evaluation Kit vs. Standard Module

Choosing the right hardware version is critical for project success:

  • PN1-S25 Core Module: Ultra-compact ($24 \times 19 \times 3.2 \text{mm}$), 3.3V power, stamp-hole (SMT) mounting. Designed for direct integration into high-volume PCB production.

  • PN1-S25-TB Evaluation Kit: A plug-and-play platform that mounts the core module onto a baseboard with standard connectors.

Expert Recommendation: Always start with the PN1-S25-TB kit for initial functional verification and PLC configuration. Once the communication logic is finalized, transition to the PN1-S25 module for final product integration to reduce development risk and time-to-market.

3. Hardware Connection Guide

3.1 Power Supply (Type-C)

The kit utilizes a Type-C interface for power, supporting DC 5V. This allows for high versatility, as it can be powered by standard phone chargers, PC USB ports, or industrial 5V power adapters.

  • Check: Ensure voltage is within $5\text{V} \pm 5\%$.

  • Indicator: The Power LED will illuminate immediately upon successful connection.

3.2 Profinet Network (RJ45)

Profinet connectivity is handled via the onboard RJ45 port, supporting 10/100M auto-negotiation.

  • Connection: Connect the kit to a Profinet-enabled PLC (e.g., S7-1200/1500) or an industrial switch using a standard shielded Ethernet cable.

  • Validation: The Link/Activity LED on the RJ45 port indicates a physical layer connection.

3.3 RS485 Serial (Modbus RTU)

The kit provides two independent RS485 channels for Modbus communication.

  • Wiring: Connect the A (+) and B (-) lines correctly to your Modbus slave devices (e.g., sensors or meters).

  • Tip: While reversing A and B won't damage the hardware, it will cause communication failure.

4. Communication Status & Monitoring

The PN1-S25-TB features several methods to diagnose system health:

  • Network LEDs: Reflect Profinet connection status. Steady lights or rhythmic flashing indicate normal operation; no light suggests a network configuration or physical cable error.

  • Serial LEDs (TX/RX): These indicate Modbus traffic.

    • TX Flashing Only: The gateway is sending requests, but the Modbus device is not responding.

    • TX & RX Flashing: Healthy bi-directional communication.

  • Software Diagnostics: Use TIA Portal’s online diagnostic tool to view real-time data packets, error counters, and GSDML file status.

5. Troubleshooting & FAQ

Problem Potential Cause Solution
Profinet Connection Fail Incorrect Device Name Ensure the "Profinet Device Name" in TIA Portal matches the hardware setting exactly.
IP Conflict Duplicate IP Address Verify the IP is in the same subnet as the PLC and no other device shares the address.
Modbus No Response A/B Lines Reversed Swap the RS485 A and B wires.
Modbus Data Error Parameter Mismatch Check if Baud Rate, Data Bits, Parity, and Stop Bits match the slave device settings.
GSDML Error Missing GSD File Download and import the correct GSDML file into your PLC configuration software.

6. Resources & Documentation

To ensure a smooth setup, users should download the following from our technical support portal:

  1. User Manual: Detailed interface definitions and electrical characteristics.

  2. GSDML File: Required for PLC (TIA Portal/Step 7) hardware identification.

  3. Configuration Tool: Software to set Modbus registers and Profinet data mapping.

Summary

The PN1-S25-TB Evaluation Kit is a robust, user-friendly tool for industrial engineers. With its Type-C power, dual RS485 ports, and easy-to-monitor status LEDs, it significantly simplifies the process of bridging Modbus devices into a Profinet ecosystem.