Understanding LED Indicators and Ports on GE Programmable Logic Controllers (PLCs)

Understanding LED Indicators and Ports on GE Programmable Logic Controllers (PLCs)

In today's era of automation, PLCs (Programmable Logic Controllers) play a vital role. Popular brands like Siemens, Yokogawa, Allen-Bradley (AB), ABB, and GE offer PLC controllers with various LED indicators. To make the most of these indicators, you need to understand their meanings.

In this article, we will delve into the LED indicators found on GE PLCs, specifically focusing on the CPL series. Additionally, we will explore the functionality of the different ports available on these controllers.

GE CPL-410 Model Overview

The GE CPL-410 model, part of the RX3iCPL410 series, is a Programmable Automation Controller (PAC) equipped with a built-in Linux server. It supports multiple programming languages, including ladder logic, structured text, functional block diagram, and C.

Key specifications of the CPL-410 model include 64MB of configurable data and program memory, 32K bits for discrete input and output, and 32K words for analog input and output. It can handle operating temperatures ranging from -40 to 70 degrees Celsius, is DIN rail mountable, supports an 18-30 VDC power supply, and has five front Ethernet ports.

Display, Lights, and Connectors on the Cpl410

LED Indications on GE CPL-410 Model

Now, let's explore the LED indications for the GE CPL-410 model:

  • µSD: This slot accommodates a Micro-SD card for external storage and program loading, with a protective cover for safety.

  • DISP: The DISP button allows access to the OLED display menu for navigation and settings related to LAN, control status, I/O status, device information, Linux OS settings, and redundancy information.

  • SEL: Used for navigating and selecting various settings.

  • RUN: Activates the OLED menu for selecting "RUN enabled" or "RUN disabled" mode on the PLC. A green indication shows "RUN" in an enabled state.

  • STOP: Sends a stop command to the PLC, enabling or disabling it.

  • PHY PRES: Indicates physical presence, associated with the Trusted Platform Module (TPM). A green light confirms a healthy condition.

  • SSD: Monitors the solid-state disk activity, with a green light indicating a healthy state.

  • TEMP: This indication alerts when the controller reaches an overtemperature condition, with an amber LED indicating excessive heat.

  • OK: Signals that the CPU is in a healthy condition.

  • OE: Confirms that the output is enabled, with a green indication when functioning correctly.

  • FRC: Activates a yellow indication when force is applied to a module or equipment, indicating the force signal is enabled.

  • FLT: This indication, in red, alerts to a system fault when an issue occurs with any module.

  • IO: Indicates the health status of the IO network, with a green indication for a healthy connection.

  • RACT: Signals the status of redundancy, with a green indication when redundant devices are active.

  • RBOK: Confirms that the redundant backup unit is in a healthy state, with a green indication.

  • GPOK: A blinking green light shows that the general purpose operation, including the Linux operating system, is running properly.

  • PWR: Indicates that the power is on and allows the controller to be reset by holding the button.

Communication Ports on the PLC


Understanding communication ports is crucial for proper operation. Here are some insights:

  • USB1: Used for Linux and allows access to keyboards, memory sticks, and other devices with properly installed drivers.

  • USB2: Assigned to the controller runtime PACS (Programmable Automation Controller).

  • LAN: These ports configure plant communication packages and hot standby redundancy, providing high-speed data synchronization between CPUs. Different LAN ports serve various functions, including primary and redundant connections.

  • Front Panel LAN: These ports are un-switchable and switchable and provide hot standby redundancy.

  • Underside LAN: Supports Serial IO protocol and is assigned to the Linux system itself.

Other Ports on the Bottom Side of the PLC

Below ports are available on the bottom side of PLC

Additional ports and connectors include Display Port, EFA (Informatica Intelligent Cloud Services), EPCSS (Energy Pack Control & Status Signal), and 24DC IN.

This article provides an overview of LED indicators and ports on GE PLCs, offering insights into their functionalities and how they can be effectively used for automation and control. 

Back to blog