IC697BEM713: Integrating with Legacy Systems and Modern Technologies

The Challenge of Integrating Old and New Technologies

In today's rapidly evolving industrial landscape, manufacturers face the persistent challenge of bridging the gap between legacy equipment and modern digital technologies. While legacy systems often represent significant capital investment and contain proven, reliable logic, they lack the connectivity, data analytics capabilities, and interoperability required for Industry 4.0. The IC697BEM713, a foundational component within GE Fanuc's Series 90-70 PLC system, epitomizes this challenge. It is a robust and reliable I/O module designed for harsh industrial environments, but its native communication protocols are a world apart from modern Ethernet-based systems. The core dilemma for plant managers is how to leverage the remaining operational life of such hardware without creating data silos that hinder overall equipment effectiveness (OEE).

Successful integration is not merely a technical exercise; it is a strategic imperative. It enables organizations to extract valuable machine data for predictive maintenance, energy monitoring, and production optimization. For instance, integrating a legacy PLC system featuring the IC697BEM713 with a modern Manufacturing Execution System (MES) can provide real-time visibility into production bottlenecks. This process, however, requires a deep understanding of both the legacy hardware's constraints and the capabilities of modern integration platforms. The goal is to create a cohesive ecosystem where data from a VF702 variable frequency drive, controlled by an older PLC, can be seamlessly consumed by a cloud-based analytics dashboard, empowering data-driven decision-making across the enterprise.

Overview of IC697BEM713 Integration Capabilities

The IC697BEM713 is a 32-channel discrete input module part of the renowned Series 90-70 PLC family. Its primary function is to interface with field devices like limit switches, push buttons, and proximity sensors, converting their physical states (on/off) into digital signals the PLC CPU can process. While the module itself does not possess native Ethernet or advanced communication ports, its integration capabilities are realized through the PLC's backplane and the CPU's communication modules. The Series 90-70 platform often utilizes the EC401-50 Ethernet Interface Module, which acts as a critical gateway.

This setup allows the data points mapped to the IC697BEM713's inputs to be exposed to a factory network. The EC401-50 module can communicate using standard protocols like SRTP (Series 90-70 Remote I/O Protocol) over Ethernet, which can then be translated to more universal protocols like Modbus TCP/IP or OPC UA by a protocol converter or a dedicated gateway device. Therefore, the integration capability of the IC697BEM713 is inherently tied to the communication options available for the host PLC rack. Understanding this hierarchical relationship is the first step in designing a successful integration strategy that can also incorporate data from other devices like the VF702 drive.

Common Communication Protocols Used in Legacy Systems

Legacy industrial systems, particularly those from the era of the Series 90-70, rely on a suite of communication protocols that are robust but often proprietary or slow by modern standards. Understanding these is crucial for integration.

• Serial Protocols (RS-232/RS-485): These were the workhorses of industrial communication for decades. Modbus RTU, a master-slave protocol running on RS-485, is exceptionally common. A PLC with an IC697BEM713 module might use a serial communication module to talk to devices like the VF702 drive using Modbus RTU.
• Proprietary Backplane Protocols: Modules like the IC697BEM713 communicate with the PLC CPU via a high-speed proprietary backplane bus. While efficient, this data is inaccessible outside the rack without a specialized communication module.
• Early Network Protocols: Before the ubiquity of TCP/IP, manufacturers developed their own network solutions. GE Fanuc's Genius I/O bus is a prime example, a peer-to-peer network for distributed I/O blocks. Integrating these often requires a gateway like the EC401-50 to bridge to Ethernet.

The primary challenge with these protocols is their lack of interoperability. A system using a proprietary protocol to read data from an IC697BEM713 cannot natively share that data with a modern SQL database or a web service without an intermediary translation layer.

Challenges of Interfacing with Older Hardware

Beyond communication protocols, physical and logistical hurdles complicate integration with legacy hardware. First is hardware obsolescence. Finding replacement parts for a Series 90-70 rack or a specific module like the IC697BEM713 becomes increasingly difficult and expensive. This scarcity forces integrators to work with extreme care, as a mistake could lead to prolonged downtime. Second, documentation is often lost or incomplete. The original logic diagrams, configuration settings, and I/O maps for the system controlling the VF702 drive may not be available, turning reverse-engineering into a time-consuming and risky endeavor.

Third, older hardware has inherent limitations. Processing power and memory are scarce resources in a legacy PLC. Adding complex communication drivers or data logging functions can overwhelm the CPU, affecting the critical real-time control of machinery. Finally, there is a skills gap. Engineers proficient in legacy programming languages like Relay Ladder Logic for these systems are retiring, while new engineers are trained on modern, software-centric platforms. This knowledge gap can stall integration projects and increase reliance on external specialists.

Using Communication Gateways and Protocol Converters

The most common and effective method for integrating a legacy system is deploying a communication gateway or protocol converter. This hardware device acts as a translator, sitting between the legacy equipment and the modern network. For a Series 90-70 system with an IC697BEM713 module, the gateway would typically connect to the PLC's serial port or a network module like the EC401-50.

The gateway performs several critical functions. It polls the PLC for data from specific memory registers associated with the IC697BEM713's input states. It then translates this data from the native protocol (e.g., SNP, SRTP) into a modern, open standard like Modbus TCP/IP, OPC UA, or MQTT. This transformed data is then published to the local network or directly to a cloud platform. For example, a gateway could read the status of a conveyor belt from the IC697BEM713 and the speed reference from a VF702 drive, combining them into a single MQTT message stream for a supervisory system. This approach isolates the legacy PLC from network traffic and security threats, preserving its stability while enabling data accessibility.

Creating Custom Interfaces

In scenarios where off-the-shelf gateways are insufficient due to highly proprietary or unusual protocols, developing a custom software interface may be necessary. This involves writing a software driver or application that can communicate directly with the legacy hardware. This application could run on a industrial PC (IPC) or a soft-PLC platform connected to the legacy network.

The development process starts with a deep analysis of the protocol used by the legacy device. For a system centered on the IC697BEM713, this might mean understanding the exact command structure to read the discrete input table from the Series 90-70 CPU. Using a programming language like Python or C#, developers can create a socket-based application that sends these custom commands, parses the responses, and reformats the data. This custom interface can then push the data to a database, a REST API, or a cloud service like AWS IoT Greengrass. While this method offers maximum flexibility, it requires significant development expertise, thorough testing, and long-term maintenance commitment, making it more costly than using a pre-built gateway.

Data Mapping and Translation

A critical, often overlooked, step in integration is data mapping and translation. Raw data from a legacy system like a point from the IC697BEM713 is often just a binary value (0 or 1) stored in a specific PLC register address (e.g., %I00512). For this data to be meaningful in a modern context, it must be mapped to a semantic information model.

This process involves creating a "tag" or data point in the new system that represents the physical asset. For example:

Furthermore, translation may be required. A value of '1' from an old system might mean "Fault" while modern systems typically use '0' for "Healthy" and '1' for "Fault". The gateway or interface software must perform this bit-level translation to ensure data consistency and accuracy across the integrated architecture. Proper data mapping is the foundation for effective data analytics and visualization.

Ethernet-Based Communication

Ethernet has become the de facto standard for industrial networking, and enabling Ethernet connectivity is a primary goal of legacy integration. For a Series 90-70 system, this is typically achieved by installing an Ethernet communication module like the EC401-50 into the PLC rack. This module allows the PLC to communicate on a TCP/IP network.

The EC401-50 supports protocols like SRTP, which allows programming software and HMIs to communicate with the PLC. However, for broader interoperability, this SRTP traffic is often converted to Modbus TCP/IP. Modbus TCP is a simple, widely supported protocol that wraps Modbus commands in a TCP packet. Once the data from the IC697BEM713 and other devices is available on the network via Modbus TCP, it can be easily read by SCADA systems, data historians, and enterprise applications. This creates a unified network infrastructure where data from a legacy PLC and a modern VF702 drive (which likely has native Ethernet/IP support) can coexist and be utilized together.

Web Services and APIs

For deep integration with IT systems like Enterprise Resource Planning (ERP) or Manufacturing Execution Systems (MES), simply having data on a network is not enough. These systems communicate through web services and Application Programming Interfaces (APIs), predominantly using REST (Representational State Transfer) principles and JSON/XML data formats.

To bridge this gap, an intermediary device is used. This could be an edge gateway, an industrial PC, or a modern PLC acting as a protocol converter. This device performs a crucial role: it aggregates data from multiple sources, including the legacy PLC housing the IC697BEM713 and the newer VF702 drive. It then structures this data into a JSON payload and exposes it through a REST API endpoint. For example, a client application could send an HTTP GET request to `http://gateway-ip/api/conveyor1/status` and receive a JSON response containing the health status from the IC697BEM713 and the current speed of the VF702 drive. This API-centric approach provides a standardized, secure, and scalable method for system-to-system communication.

Cloud Integration

Cloud integration represents the pinnacle of modern industrial connectivity, enabling centralized data storage, advanced analytics, and remote monitoring across multiple facilities. Integrating a legacy component like the IC697BEM713 with the cloud involves a multi-step process centered on an edge computing device.

The edge device (e.g., a gateway or IPC) collects data from the legacy system. It then uses a lightweight, secure messaging protocol like MQTT (Message Queuing Telemetry Transport) to publish this data to a cloud IoT platform such as AWS IoT Core, Microsoft Azure IoT Hub, or Google Cloud IoT Core. MQTT is ideal for constrained networks and unreliable connections. The cloud platform ingests the data, which can then be stored in a time-series database, visualized in real-time dashboards, and processed by machine learning algorithms for predictive analytics. This allows a maintenance manager in Hong Kong to monitor the health of a VF702 drive and its associated control signals from the IC697BEM713 on a machine located in a Shenzhen factory, facilitating proactive maintenance and reducing unplanned downtime.

Protecting Data During Integration

Integrating legacy systems, which were never designed with cybersecurity in mind, introduces significant risks. A primary concern is protecting data integrity and confidentiality as it moves from the isolated operational technology (OT) network to the information technology (IT) network or the cloud. The first line of defense is network segmentation. Legacy devices like the PLC controlling the IC697BEM713 should remain on a separate OT network segment, with communication to the IT network strictly controlled through a firewall.

Data-in-transit must be encrypted. When using modern protocols like MQTT or HTTPS for cloud integration, TLS/SSL encryption should be mandatory to prevent eavesdropping and man-in-the-middle attacks. For data passing through a gateway, ensure the gateway itself is hardened—changing default passwords, disabling unused services, and applying regular security patches. It's also critical to implement strict access control lists (ACLs) on the gateway and the cloud platform, ensuring that only authorized users and applications can read or write data related to critical assets like the VF702 drive.

Implementing Security Measures for Both Legacy and Modern Systems

A holistic security strategy must address the weaknesses of the legacy environment while leveraging the strengths of modern security tools. For the legacy side, this involves "air-gapping" as much as possible, meaning no direct internet connection. If external communication is necessary, it should be through a unidirectional gateway that only allows data out, not commands in. Regularly monitoring network traffic for anomalies that could indicate a compromise is also crucial.

For the modern part of the architecture, standard IT security practices apply. This includes:

• Using VPNs for remote access.
• Implementing multi-factor authentication (MFA) for all cloud and HMI interfaces.
• Maintaining detailed audit logs of all data access and configuration changes.

The integration point itself, such as the gateway translating data for the EC401-50 module, becomes a critical security asset. It should be configured to perform data validation and sanitization, blocking any malformed packets that could be used to attack either the legacy or modern system. This defense-in-depth approach creates a resilient security posture.

Successful Integration Projects

A notable case study from Hong Kong's industrial sector involved a major textile manufacturer facing efficiency losses due to a lack of visibility into their aging dyeing machines. The control system was based on a Series 90-70 PLC with IC697BEM713 modules interfacing with sensors and actuators. The challenge was to integrate this data with a new MES without replacing the reliable, albeit old, control hardware.

The solution involved installing a modern edge gateway. This gateway connected to the PLC's serial port and communicated using a custom driver developed for the legacy protocol. It successfully read data from the IC697BEM713 modules, including tank level sensors and valve statuses. Simultaneously, it connected via Modbus TCP to new VF702 drives that had been installed to upgrade the pump motors. The gateway aggregated all this data, translated it into OPC UA, and made it available to the MES. The result was a 15% reduction in dyeing cycle times and a 20% decrease in energy consumption due to optimized pump control and better batch scheduling, demonstrating a clear return on investment.

Lessons Learned

Several key lessons emerge from successful integration projects. First, thorough planning and a proof-of-concept (PoC) phase are non-negotiable. Testing the communication between the gateway, the legacy PLC (IC697BEM713), and modern devices (VF702) in a non-production environment prevents costly disruptions. Second, choosing the right gateway platform is critical; it should support a wide range of protocols and be scalable for future expansions.

Third, involve all stakeholders from the beginning, including maintenance technicians familiar with the old system and IT staff responsible for the new network. Their combined knowledge is invaluable. Finally, document everything meticulously—the data map, network topology, gateway configuration, and API specifications. This documentation is essential for troubleshooting, future modifications, and ensuring knowledge transfer, safeguarding the investment for years to come.

Benefits of Integration

The benefits of successfully integrating legacy systems like those using the IC697BEM713 are substantial. It extends the operational life of capital assets, protecting previous investments. It unlocks trapped data, transforming it into actionable intelligence for improving Overall Equipment Effectiveness (OEE), reducing downtime, and optimizing energy usage. Integration also enhances operational flexibility, allowing for the gradual adoption of new technologies like the VF702 drive without a disruptive rip-and-replace approach. By creating a connected factory floor, organizations can achieve higher levels of automation, better quality control, and improved responsiveness to market demands.

Future Trends in System Integration

The future of system integration is moving towards even greater abstraction and standardization. Technologies like OPC UA FX (Field eXchange) aim to provide a unified, semantic data model across devices from different vendors, simplifying the integration of everything from a legacy IC697BEM713 to a cutting-edge robot. The adoption of 5G for wireless industrial communication will offer high bandwidth and low latency for mobile assets and difficult-to-wire areas. Furthermore, AI-powered integration platforms will emerge, capable of automatically discovering assets on a network, suggesting data mappings, and even predicting potential communication failures before they occur, making the integration of legacy equipment a faster, more reliable, and ultimately more valuable endeavor.