Technical Specifications

FAQ

1. What is the Siemens 6AG1055-1CB00-7BA2 Expansion Module used for?

The Siemens 6AG1055-1CB00-7BA2 is a SIPLUS LOGO! DM8 24 digital expansion module designed to extend the input and output capacity of compatible LOGO! 8 controllers. It provides four digital inputs and four transistor outputs, allowing a control system to connect additional switches, sensors, relays, and other compatible devices. It is commonly used in small machine automation, HVAC control, pump systems, and auxiliary equipment where additional digital I/O points are required.

2. Which PLC or logic controller is compatible with this expansion module?

This module is designed for the Siemens LOGO! 8 system and is based on the standard module 6ED1055-1CB00-0BA2. Before installation, confirm that the existing LOGO! basic module supports this expansion type and that the system configuration allows the required number of expansion modules. Compatibility should be checked against the controller’s hardware version and documentation rather than assumed from the LOGO! product name alone.

3. What are the power supply requirements for the 6AG1055-1CB00-7BA2?

The module uses a 24 V DC supply, with a permissible voltage range of 20.4–28.8 V DC. A stable supply helps prevent communication interruptions, incorrect signal detection, and unexpected output behavior. During commissioning, measure the supply voltage at the module terminals and verify the wiring polarity. The power supply must also have sufficient capacity for the complete LOGO! system and its connected loads.

4. How do the four digital inputs work?

The four digital inputs accept compatible 24 V DC signals from devices such as push buttons, limit switches, and digital sensors. An input signal below 5 V DC is recognized as logic 0, while a signal above 12 V DC is recognized as logic 1 under the specified conditions. Signals within the transition region should be avoided because their interpretation may be uncertain. Proper grounding, wiring separation, and noise control help maintain reliable input detection.

5. What type of output does this module provide, and what loads can it control?

The module provides four 24 V DC transistor outputs, each rated at 0.3 A under specified operating conditions. Unlike relay outputs, transistor outputs are electronic switching devices intended for compatible DC loads. They can be used to control suitable indicators, small actuators, and interface relays, provided the electrical ratings are respected. The outputs include short-circuit protection, but this does not remove the need to observe wiring limits and load specifications. Loads exceeding the rated current should be controlled through suitable external interface devices.

6. What is the purpose of the conformal coating on the SIPLUS version?

The conformal coating helps protect the electronic assemblies against specified environmental stresses and contamination. Combined with the rated operating temperature range of -40°C to +70°C and a minimum startup temperature of -25°C, it makes the module suitable for certain demanding industrial environments. However, the coating does not change the IP20 protection rating or make the unit waterproof. Appropriate enclosure protection and installation practices are still necessary where dust, moisture, or condensation may be present.

7. How should the module be installed and configured?

The module is designed for mounting on a standard 35 mm DIN rail and connects to a compatible LOGO! 8 basic module through the system’s expansion interface. Before installation, isolate the equipment from its power source and follow the manufacturer’s safety instructions. After mounting and wiring, verify the supply voltage, input signal connections, and output load ratings. Then check the controller’s hardware configuration and test each input and output individually before returning the machine to normal operation.

8. What should be checked if the expansion module’s inputs or outputs do not work correctly?

Start by checking the 24 V DC supply and inspecting the expansion connection between the module and the LOGO! basic unit. For input problems, measure the field signal at the input terminal and confirm that it reaches the required logic threshold. For output problems, check the control program, output wiring, load current, and connected device. If a short circuit or overload is suspected, isolate the affected circuit and inspect the wiring before restoring power. Persistent faults may require checking the controller configuration or testing the module with a known-compatible system.