Siemens LOGO! 9 Programming Part 1 - Hardware & Programming

Q: When will LOGO! 8 be discontinued?

Phase-out begins **Q1 2027** for PM410-series modules and **Q1 2032** for PM490-series. Spare parts and support continue for 10 years after phase-out per Siemens lifecycle policy. New designs should standardize on LOGO! 9. --- This is **Part 1 of 4** in our LOGO! 9 programming series. Up next: - **Part 2** — Timers, Counters, Real Examples - **Part 3** — Analog, Math, Comparators - **Part 4** — Communication, Web Server, Modbus, TIA Integration Want hands-on training on Siemens LOGO! and the broader S7 platform? Our [PLC programming courses at controlbyte.tech](https://controlbyte.tech) cover LOGO! 9, S7-1200, S7-1500, and full automation projects with real lab hardware.

The Siemens LOGO! 9 is the new generation of Siemens’ compact logic controller, launched in 2026 to replace the LOGO! 8 family. It’s not a small upgrade — LOGO! 9 doubles the function block capacity, adds a 2.4″ color touch display, switches to 32-bit float math, and ships with built-in security and a cross-platform programming tool (Soft Comfort V9 runs on Windows, Linux, and macOS).

This is Part 1 of a 4-part LOGO! 9 series: hardware overview, wiring, Soft Comfort V9 install, and your first program. Parts 2-4 cover timers/counters, analog/math, and communication/web.

What’s New in LOGO! 9 vs LOGO! 8

The headline differences:

Feature	LOGO! 8	LOGO! 9
Display	6 lines monochrome	2.4″ color, touch (BM with display)
Function blocks	400 max	800 max
Math precision	32-bit integer	32-bit floating point
Local DI / DQ	24 / 20	64 / 60
Local AI / AQ	8 / 8	16 / 16
Network I/O	NI 64, NQ 64	NI 512, NQ 480, NAI 128, NAQ 128
Programming SW	Soft Comfort V8.x (Windows only)	Soft Comfort V9 (Win + Linux + macOS)
Security	Optional password	Built-in security wizard, UMAC user mgmt
Storage	microSD	microSD (formattable in BM)
Compliance	—	EU CRA-ready
New module	—	LOGO! CIM — 4G/LTE, 4× Ethernet, REST API, AWS Cloud, MQTT

LOGO! 8 stays orderable until Q1 2027 (PM410 modules) and Q1 2032 (PM490 modules), so existing projects have a long runway. New designs should default to LOGO! 9.

Hardware Lineup

A typical LOGO! 9 station consists of:

Base Module (BM) — CPU + I/O, with or without 2.4″ touch display
Power supply — 12/24 VDC or 115/230 VAC variants (built into BM in most variants)
Expansion modules — DM digital, AM analog, RS485 communication
LOGO! TDE (optional) — 4.3″ external touch display via Ethernet
LOGO! CIM (optional, NEW) — connectivity gateway: 4 Ethernet ports, Modbus TCP/RTU, 4G/LTE PCIe slot, REST API, AWS, SMS, GPS, VPN
LOGO! CSM — 4-port unmanaged switch
LOGO! CMK2000 — KNX gateway
microSD card — program backup, web pages, recipes; formattable directly in the BM (new in LOGO! 9)

A small panel typically has: 1× BM with display, 1-2× DM digital expansion, optionally 1× AM analog, 24 VDC supply, and a microSD card.

Wiring Basics for Siemens LOGO! 9

For a 24 VDC variant (most common):

24 VDC + ──┬── L+ on BM
           ├── L+ on each expansion module
           └── DI common (sourcing inputs)
24 VDC - ──┬── M on BM
           └── M on each expansion module

DI 1 ────── push button NO ── 24 VDC +
DQ 1 ────── relay coil ────── 24 VDC -      (relay output variant)
                              or transistor variant: load to 0 V

For 230 VAC variants, inputs accept 230 V AC directly — no separate I/O power supply needed, but never mix 24 V and 230 V wiring on the same module.

Installing LOGO! Soft Comfort V9

Soft Comfort V9 is cross-platform: Windows 10/11, Ubuntu 22.04+, macOS 13+. Download from the Siemens Industry Mall.

Install steps (Windows):

Run LSC_V9.x_Setup.exe as Administrator — about 800 MB
Choose Standard edition (Demo gives full programming, only commissioning is restricted)
Launch — first start initializes the project library (~30 s)
Connect the BM to your laptop via Ethernet (LOGO! 9 default IP 192.168.0.1 — set laptop NIC to 192.168.0.100)

Linux/macOS install: download the .deb (Ubuntu) or .dmg (macOS) package, install, launch — same UI, same project file format. You can move .lsc projects between OSes without conversion.

Secure Setup — First Boot Siemens LOGO! 9

LOGO! 9 ships with secure-by-default behavior. On first power-up of a fresh BM:

The display shows the Setup Wizard
You’re forced to set an admin password (minimum 8 characters, complexity enforced)
You configure the device name and IP address
You choose which services to enable (web server, modbus, OPC UA — all OFF by default)

This matters: the EU Cyber Resilience Act (CRA) comes into force in 2027, and “secure by default” is a hard requirement. LOGO! 9 is designed to comply out of the box.

The Soft Comfort V9 Security Wizard mirrors the same flow when you create a new project — it walks you through users, roles, and which interfaces should accept connections.

Your First Program — Start/Stop in FBD

LOGO! programs use Function Block Diagram (FBD) by default. Goal: a basic latched start/stop.

In Soft Comfort V9:

File → New → choose LOGO! 9 as the device, pick the BM variant
Drag onto the canvas: 2× Input (I), 1× Output (Q), 1× Latching Relay (RS)
Wire it up:

– I1 (Start button) → S (set) input of RS – I2 (Stop button) → R (reset) input of RS – RS output → Q1

Tools → Simulation — toggle I1 (Q1 turns on, latched), toggle I2 (Q1 turns off)

Download to the BM: PLC → Transfer → PC → LOGO! — pick the device from the discovery list, enter the admin password.

On the BM display, switch to RUN mode. Press the wired start button — Q1 LED illuminates, contactor pulls in. Stop button drops it.

That’s a working LOGO! 9 program. In Part 2 we’ll add timers, counters, real-world examples (lighting control, motor with delay, pulse counter), and the new LCD message editor for the touch display.

Quick Tips From Commissioning Siemens LOGO! 9

Always set a static IP before deployment (BM → Network → IP Address). DHCP is convenient on a bench but breaks remote access in the field.
Enable only the services you need — HTTP off if no web server, OPC UA off if no SCADA, Modbus off if no third-party. CRA compliance and reduced attack surface.
Back up to microSD after every commissioning visit (BM → Card → Save). LOGO! 9 lets you format the card from the BM if it’s blank.
Soft Comfort V9 has an emulator — test full programs offline including the touch display, network communication, and LCD messages. Use it before every download.

FAQ

Can I run LOGO! 8 programs on LOGO! 9?

Soft Comfort V9 imports LOGO! 8 projects automatically. The conversion handles 95% of cases — the parts that need attention are integer-to-float math conversions and any custom LCD message formatting. Run a full simulation test before commissioning.

Does LOGO! 9 support OPC UA?

Yes — LOGO! 9 BMs include an OPC UA server (DA profile, read/write of I, Q, M, V variables). It’s disabled by default; enable it through Soft Comfort V9 → Project Properties → Communication.

What’s the difference between LOGO! 9 with and without display?

Functionally identical CPU. The version without display is ~€60 cheaper and slightly smaller, but you lose the touch interface for local diagnostics. Most OEMs pick the version with display for serviceability.

Is Soft Comfort V9 backwards compatible with LOGO! 8 hardware?

Yes — V9 programs both LOGO! 8 and LOGO! 9 BMs. You select the target device when creating the project. Internally V9 uses different feature sets per target.

When will LOGO! 8 be discontinued?

Phase-out begins Q1 2027 for PM410-series modules and Q1 2032 for PM490-series. Spare parts and support continue for 10 years after phase-out per Siemens lifecycle policy. New designs should standardize on LOGO! 9.

—

This is Part 1 of 4 in our LOGO! 9 programming series. Up next:

Part 2 — Timers, Counters, Real Examples
Part 3 — Analog, Math, Comparators
Part 4 — Communication, Web Server, Modbus, TIA Integration

Want hands-on training on Siemens LOGO! and the broader S7 platform? Our PLC programming courses at controlbyte.tech cover LOGO! 9, S7-1200, S7-1500, and full automation projects with real lab hardware.