Siemens Introduces LOGO! 9 with Expanded I/O and New AM4 Analog Module

More capacity in a compact controller

LOGO! 9 doubles the previous generation’s function-block capacity to 800. Depending on the configuration, a system can accommodate up to 64 digital inputs, 60 digital outputs, 16 analog inputs and 16 analog outputs. These are system-level expansion limits, rather than the channel count of an individual module.

Siemens has also introduced a color touchscreen on display-equipped Basic Modules, alongside versions without a display. LOGO! Soft Comfort V9 supports engineering on Windows, macOS and Linux. Secure Boot, protected communication and four user-management roles form part of the platform’s security features.

What the AM4 specification means in practice

Match the electrical signal before scaling the value

The available voltage and current ranges let the same module family serve different transmitter and actuator interfaces. A channel still needs the correct wiring and configuration for the connected device. A 4–20 mA pressure transmitter and a 0–10 V actuator command cannot be treated as equivalent signals simply because both are analog.

For temperature measurement, the absence of a direct Pt100 input matters: a bare resistance sensor is not a 0–10 V or 4–20 mA transmitter. An appropriate signal converter or a compatible dedicated temperature module is needed instead of connecting the sensor as though it were a current-loop source.

Resolution is not the same as measurement accuracy

Siemens specifies 12-bit inputs and 16-bit outputs for this order number. These conversion resolutions must be distinguished from the selectable process-value representation and floating-point support of the LOGO! 9 analog system. Changing a program’s number format does not improve the sensor’s accuracy or create additional physical converter resolution. The complete measurement chain still depends on the transmitter, signal conditioning, wiring and module error limits.

One possible application is a small pressure or level-control assembly that needs both a measured value and a proportional command to an external actuator. AM4 supplies the signal interface; the Basic Module supplies the programmed control behavior. Output range, actuator input requirements and the response to an invalid measurement must be defined as part of that application.

Plan the complete expansion assembly

The LOGO! 9 Backbone Bus connects the expansion modules to the Basic Module. The platform supports up to 16 expansion modules, subject also to its separate digital and analog channel limits. Both limits must be checked: an available module position does not mean that the system has unused analog-channel capacity.

AM4 still requires its specified 24 V DC supply. Its 85 mA figure is a typical consumption value, not a maximum design allowance for the entire assembly or its field devices. Size the power supply using the applicable maximum loads, including the Basic Module, other extensions and separately powered transmitters or actuators.

The 35.5 mm module width helps estimate rail space, while the 58 mm depth is the device dimension rather than a complete wired-cabinet clearance. Allow room for terminals and cable routing. IP20 and the no-condensation condition should also be considered when selecting an enclosure and assessing the actual panel temperature.

From announcement to availability

These are Siemens’ published platform milestones. Availability varies by product variant and local ordering conditions; they do not establish Apter Power stock or dispatch timing.