TIA Selection Tool is Siemens's free hardware selection and configuration tool. Use it to choose SIMATIC S7-1200 or S7-1500 CPUs, add local or ET 200SP distributed I/O, select suitable HMI and SINAMICS drive components, validate compatibility and power requirements, generate a complete product list, and transfer the supported hardware configuration into TIA Portal. It is available in cloud and desktop versions; the best choice depends on whether you need browser-based collaboration or offline project work.
- Select Siemens S7-1200, S7-1500 and ET 200SP hardware according to I/O, communication, memory and performance requirements
- Compare the TIA Selection Tool cloud and desktop versions and choose the correct workflow for office, training or site work
- Check module compatibility and power requirements before generating the bill of materials or transferring hardware to TIA Portal
- Use MLFB order numbers to verify exact Siemens product variants, replacements and spare parts
What Is Siemens TIA Selection Tool?
TIA Selection Tool (TST) is Siemens's free engineering configurator for building the hardware side of a project before you buy or program anything. You drag a CPU onto a virtual rack, add I/O, communication and power modules into free slots, and the tool checks that everything you've picked is actually compatible — correct slot rules, current draw against the power supply's budget, and firmware/order-number matches. The output is a parts list you can quote or order, plus a configuration file you can bring straight into TIA Portal.
It's easy to confuse TST with two other tools in the Siemens ecosystem:
- TIA Portal is where you write and download the actual program logic — TST never touches program blocks, only hardware.
- Industry Mall is where you actually place the purchase order once your parts list is final — TST can hand off the list there directly.
- TIA Selection Tool is the only one of the three built specifically to catch selection mistakes before hardware is ordered or wired.
Want to practice this on real hardware?
Live TIA Portal session covering hardware configuration, TIA Selection Tool exports, and commissioning — Pune classroom or online.
Siemens PLC Module Types Explained (With Pictures)
Before you open TIA Selection Tool, it helps to know what each module in its catalog actually does. An S7-1500 station is built from a few module types that always sit in the same order on the mounting rail: the PM load supply (no slot), the system power supply in slot 0, the CPU in slot 1, then I/O, communication and technology modules from slot 2 onwards. Every module carries a colour stripe in the pictures below so you can spot its type at a glance.
Try it: build an S7-1500 station the way TIA Selection Tool does
This virtual rack works like the configurator inside TIA Selection Tool. Click a module in the catalog to place it, click any module to see what it does and its order number, and watch the backplane power bar fill as the CPU powers more modules. When it turns red, add a PS 60 W in slot 0. Add a module from Other families to see the red compatibility error, then press Check configuration to get the parts list, complete with memory card and front connectors.
The virtual rack is a training model of the main S7-1500 rules (CPU in slot 1, PS in slot 0, up to 30 modules in slots 2 to 31, about 10 W backplane feed from CPU 1511-1 PN). Power values per module are approximate; TIA Selection Tool uses the full Siemens product data.
Every module type at a glance
Load power supply (PM)
Converts 120/230 V AC mains into the 24 V DC that the CPU, the modules' load voltage and field sensors need. In an S7-1500 station the PM sits on the mounting rail left of the CPU but is not connected to the backplane, so it has no slot number.
Check in TIA Selection Tool: add up the 24 V load of the CPU, modules, sensors and HMI, then keep about 20% spare.
System power supply (PS)
Feeds power into the S7-1500 backplane bus. The CPU can supply a limited amount by itself; when a station has many modules, a PS in slot 0 provides the extra power.
Check in TIA Selection Tool: the power balance of the station. TIA Selection Tool warns when the backplane is overloaded.
CPU (central processing unit)
The brain of the station: it runs your program, shows status and diagnostics on its front display, and provides PROFINET interfaces for HMI, drives and remote I/O. It always sits in slot 1.
Check in TIA Selection Tool: work memory, number of PROFINET interfaces, motion and fail-safe needs, and the firmware version.
Digital input module (DI)
Reads ON/OFF signals: push buttons, selector switches, limit switches, proximity and photo sensors. HF (high feature) modules add channel diagnostics.
Check in TIA Selection Tool: 24 V DC or 230 V AC, the diagnostics you need (BA, ST or HF), and 15 to 20% spare channels.
Digital output module (DQ)
Switches loads ON and OFF: contactor coils, lamps, hooters and solenoid valves. Transistor outputs are fast and suit 24 V DC loads; relay outputs handle AC or DC loads but switch slower and wear over time.
Check in TIA Selection Tool: load current per channel, AC or DC, and how often the output switches.
Analog input module (AI)
Reads a changing value such as 4 to 20 mA, 0 to 10 V, RTD or thermocouple from pressure, level, flow and temperature sensors. The PLC program then scales it to engineering units.
Check in TIA Selection Tool: signal type per channel, 2-wire or 4-wire transmitters, and resolution.
Analog output module (AQ)
Sends a variable voltage or current signal out: a VFD speed reference, a control-valve position or a panel meter.
Check in TIA Selection Tool: voltage or current output and the input range of the receiving device.
Analog combo module (AI/AQ)
Analog inputs and outputs on one module. Useful for small control loops where one transmitter and one valve or drive belong together.
Check in TIA Selection Tool: that the input and output signal types both match your field devices.
Communication module (CM / CP)
Adds a network the CPU does not have built in: serial RS422/485 for Modbus RTU, PROFIBUS, or an extra Ethernet port. On S7-1500 these modules sit in any slot from 2 onwards, just like I/O modules. Communication processors (CP) carry a 6GK7 prefix.
Check in TIA Selection Tool: protocol, port type and how many devices sit on the network (VFDs, energy meters, controllers).
Technology module (TM)
Does time-critical jobs in hardware: high-speed counting, encoder reading or positioning, independent of the CPU scan time.
Check in TIA Selection Tool: maximum input frequency, encoder type and number of channels.
Front connector
S7-1500 I/O and technology modules are delivered without the wiring connector. The field wires land on a separate front connector that plugs into the module, so a module can be swapped without rewiring.
Check in TIA Selection Tool: one front connector per I/O module on the parts list, and screw or push-in type to suit your panel shop.
SIMATIC Memory Card
Stores the program and can update firmware. An S7-1500 CPU does not run without a memory card, so it must always be on the parts list.
Check in TIA Selection Tool: card size against the project, and never format it in Windows.
Interface module (IM), ET 200SP
The head of a remote I/O station. It connects ET 200SP I/O modules to the S7-1500 CPU over PROFINET, so field wiring stays close to the machine.
Check in TIA Selection Tool: network type, the maximum number of modules per station and that the server module closes the station.
BaseUnit (BU), ET 200SP
The terminal base each ET 200SP I/O module plugs into. A light BaseUnit starts a new potential group (fresh 24 V feed); a dark one continues the group to its left.
Check in TIA Selection Tool: the BaseUnit type that TIA Selection Tool lists for each module and where each new potential group begins.
How to Read Siemens MLFB Order Numbers
Every Siemens module carries an MLFB — short for Maschinenlesbare Fabrikatebezeichnung, or "machine-readable product designation" — printed on its nameplate and shown against every item inside TIA Selection Tool. Learning to read it is what lets an engineer glance at a rack, or a part number on a purchase order, and know instantly whether they're looking at a power supply, a CPU, or an I/O module, and which sub-variant it is — without opening a catalog. This is arguably the most-used, everyday function of TST on the plant floor: pasting or searching an MLFB to confirm exactly what a module is before it's wired in or reordered.
A standard SIMATIC S7 MLFB follows a fixed digit pattern after its product-series prefix (for example 6ES7). Three digit positions in that block carry the meaning engineers look up day to day: the 1st identifies the CPU/product family, the 2nd identifies the module type, and the 3rd identifies the specific sub-type within that module type.
MLFB decoder: type any Siemens catalog number
Paste the order number from a nameplate, a quotation or a TIA Selection Tool parts list. The decoder splits it into its blocks and explains each digit.
Order-number prefix: which product range is it?
The first four characters tell you the product range before you read anything else. On a mixed parts list from TIA Selection Tool you will see several of these side by side.
| Prefix | Product range | Example |
|---|---|---|
| 6ES7 | SIMATIC S7 controllers, I/O modules, accessories | 6ES7 511-1AK02-0AB0 (CPU 1511-1 PN) |
| 6EP1 | Power supplies (SITOP, PM load supplies) | 6EP1332-4BA00 (PM 70 W) |
| 6GK | Industrial communication: CPs, SCALANCE switches | 6GK7 543-1AX00-0XE0 (CP 1543-1) |
| 6AV2 | SIMATIC HMI panels | 6AV2 123-2GB03-0AX0 (KTP700 Basic) |
| 6SL3 | SINAMICS drives and drive components | SINAMICS G120 / V20 / S120 families |
| 6XV1 | Cables: PROFIBUS, PROFINET, Industrial Ethernet | PROFINET and PROFIBUS bus cable |
1st Position — Product Family
| 1st digit | Product family | Example |
|---|---|---|
| 1 | ET 200 distributed I/O (ET 200SP and others) | 6ES7 131-6BF01-0BA0, ET 200SP DI 8 |
| 2 | S7-1200 | Compact controller family (6ES7 2xx) |
| 3 | S7-300 | 6ES7 315-2AH14-0AB0, CPU 315-2 DP |
| 4 | S7-400 | 6ES7 414-3XM07-0AB0, CPU 414-3 |
| 5 | S7-1500 and ET 200MP | 6ES7 511-1AK02-0AB0, CPU 1511-1 PN |
| 8 | Engineering software and licences | STEP 7 (TIA Portal) licences |
| 9 | General accessories | 6ES7 954-8LC03-0AA0, memory card |
2nd Position — Module Type
| 2nd digit | Module type | S7-1500 example |
|---|---|---|
| 0 | System power supply (PS) | 6ES7 505-0RA00-0AB0, PS 60 W |
| 1 | CPU | 6ES7 511-1AK02-0AB0, CPU 1511-1 PN |
| 2 | Digital module (DI / DQ) | 6ES7 521-1BH00-0AB0, DI 16 × 24 V DC HF |
| 3 | Analog module (AI / AQ) | 6ES7 531-7KF00-0AB0, AI 8 × U/I/RTD/TC ST |
| 4 | Communication module (CM) | 6ES7 541-1AB00-0AB0, CM PtP RS422/485 HF |
| 5 | Technology module (TM) | 6ES7 550-1AA00-0AB0, TM Count 2 × 24 V |
| 9 | Mechanical accessory (rail, front connector) | 6ES7 590-1AB60-0AA0 rail, 6ES7 592-1AM00-0XB0 front connector |
ET 200SP numbers (1st digit 1) use their own pattern: 13x are I/O modules (131 = DI, 132 = DQ, 134 = AI, 135 = AQ), 155 is the interface module and 193 is the BaseUnit.
3rd Position — Sub-Type (Read Together With the 2nd Digit)
The 3rd position only makes sense once you know the 2nd digit's module type. It narrows that type down to the exact sub-variant:
| Module type (2nd digit) | 3rd digit | Meaning | Example |
|---|---|---|---|
| 0 — Power supply | 5 or 7 | Power-supply variant by rating and build | 505 = PS 25 W / PS 60 W, 507 = PS 190 W |
| 1 — CPU | model | Read all three digits as the CPU model | 511 = CPU 1511, 513 = CPU 1513, 515 = CPU 1515, 516 = CPU 1516 |
| 2 — Digital | 1 / 2 / 3 | 1 = DI, 2 = DQ, 3 = DI/DQ combo | 521 = DI module, 522 = DQ module, 523 = DI/DQ module |
| 3 — Analog | 1 / 2 / 4 | 1 = AI, 2 = AQ, 4 = AI/AQ combo | 531 = AI module, 532 = AQ module, 534 = AI/AQ module |
| 4 — Communication | 1 and others | Interface variant | 541 = CM PtP (serial) |
| 5 — Technology | 0 and others | Technology variant | 550 = TM Count |
After the first dash: version, channels and generation
The second block tells you the electrical version and size of the module. Read it with the first block, because the same letter can mean different things on a CPU and on an I/O module.
| Position | DI 16: 521-1BH00-0AB0 | Relay DQ 8: 522-5HF00-0AB0 | What it tells you |
|---|---|---|---|
| Design digit | 1 = 24 V DC digital design | 5 = AC / relay design | Construction variant of the module |
| Version letter | B = 24 V DC | H = relay | On digital modules: B = 24 V DC, F = 120/230 V AC, H = relay |
| Size letter | H = 16 channels | F = 8 channels | On I/O modules this letter gives the channel count (see the next table) |
| Version number | 00 = product version | 00 = product version | Higher means a newer version (e.g. CPU 1511-1 PN ...AK02). Keep it when ordering spares |
| Last block | 0AB0 | 0AB0 | Delivery version. Copy it exactly (0AB0 is typical for S7-1500, 0AA0 for BA modules) |
Channel-count letter on I/O modules
| Letter | Channels | Example |
|---|---|---|
| B | 2 | 6ES7 135-6HB00-0DA1, ET 200SP AQ 2 |
| D | 4 | 6ES7 532-5HD00-0AB0, AQ 4 × U/I ST |
| E | 6 | 6ES7 534-7QE00-0AB0, AI 4 / AQ 2 ST |
| F | 8 | 6ES7 531-7KF00-0AB0, AI 8 ST; 6ES7 522-5HF00-0AB0, DQ 8 relay |
| H | 16 | 6ES7 521-1BH00-0AB0, DI 16 HF; 6ES7 522-1BH01-0AB0, DQ 16 ST |
| L | 32 | 6ES7 521-1BL00-0AB0, DI 32 HF |
These patterns hold across S7-1500 and ET 200SP I/O, but Siemens does not publish them as a guaranteed rule. Use them to read a number quickly, then confirm the exact product in TIA Selection Tool or Siemens Industry Mall before you order.
The firmware version printed on the nameplate (for example V3.1) is not part of the MLFB. TIA Selection Tool and TIA Portal ask for it separately, and it must match the hardware you install.
Once you can read these positions you can sort a box of unlabelled spares, check a spare-parts order against the panel, or confirm a nameplate photo from site without searching the full catalog. Inside TIA Selection Tool every module tile shows its full MLFB beside its description, so the tool doubles as a live reference while you configure.
TIA Selection Tool Cloud vs Desktop
TIA Selection Tool is available as a browser-based cloud application and a Windows desktop application. The cloud version is convenient for quick access, shared projects and browser-based work, while the desktop version is better for offline engineering, site visits and locally stored project files. Before starting either version, confirm the following:
- mySiemens account: free to create, and required to save a project in the web version or place an order from your finished parts list.
- Web vs. offline app: the browser version needs a stable internet connection; the offline desktop app is better for site visits with poor connectivity and keeps projects as local files.
- Product family in mind: know roughly which CPU family you're configuring — SIMATIC S7-1200, S7-1500, drives, or SIMOCODE — before you start, since the module catalogue is filtered by family.
- Process requirements on hand: a rough I/O count and communication protocol (PROFINET, PROFIBUS, etc.) so you don't have to restart the rack halfway through.
Three Ways to Access TIA Selection Tool — and When to Use Each
TST is available in three forms, and picking the right one saves you from redoing work:
| Method | When to use it | What you get |
|---|---|---|
| Web-based TIA Selection Tool | Quick configuration from any machine with a browser, no install needed | Cloud-saved project with the same rack-building features |
| Offline installed application | Working without reliable internet, e.g. at a customer site | Full functionality with local file storage, faster for large stations |
| Import from an existing TIA Portal project | You already have a project and just need a matching parts list | TST reads the hardware config and generates the bill of materials automatically |
Configure S7-1200, S7-1500 and ET 200SP
- Open TIA Selection Tool in your browser, or launch the offline desktop app, and sign in with your mySiemens account.
- Click Create new project > Add new station.
- Choose your product family (for example, SIMATIC S7-1500) and drag the CPU you need onto the rack.
- Add signal, communication and power modules into the free slots, watching the power budget bar as you go.
- Resolve any red compatibility warnings TST raises before continuing — these flag slot or firmware conflicts.
- Click Check configuration to validate the whole rack in one pass.
- Generate the parts list, export the configuration, and save the project with a clear, dated name.
- Cross-check the parts list against the physical panel or spec sheet before placing an order.
S7-1200 PLC Selection Checklist
- Confirm the required digital and analog I/O count, including future expansion.
- Select the CPU according to program memory, communication ports, motion functions and fail-safe requirements.
- Add signal boards, signal modules and communication modules only after checking CPU support and available expansion capacity.
- Verify the supply voltage, field-voltage requirements, front connectors and memory-card requirements in the generated product list.
S7-1500 PLC Selection Checklist
- Choose between standard, compact, technology, fail-safe, redundant or other supported CPU variants according to the application.
- Compare processing performance, work memory, PROFINET interfaces, motion-control resources and diagnostics.
- Add S7-1500 or ET 200MP modules in the correct rack order and monitor the station power calculation.
- Reserve capacity for future communication processors, technology modules and additional I/O.
ET 200SP Remote I/O Configuration
For distributed I/O, add an ET 200SP station and select the interface module that matches the required network. Then add BaseUnits, digital and analog I/O, technology modules, motor starters or other supported modules in the correct sequence. Check potential groups, load-group requirements, server-module placement and station-width limits before final validation.
Select Siemens HMI and SINAMICS Drives
TIA Selection Tool is not limited to PLC racks. Use the relevant product configurators to include visualization and drive components in the same engineering workflow. Available product options can vary with the current catalog and selected region, so always validate the final order numbers before purchase.
SIMATIC HMI Selection
- Select the panel family according to screen size, resolution, touch operation and installation environment.
- Check the required PROFINET, Ethernet or other supported interfaces and confirm compatibility with the selected controller.
- Include mounting accessories, memory media, cables and power-supply items needed for the complete panel installation.
- For new projects, compare the supported SIMATIC HMI Unified panel options with the application and TIA Portal engineering version.
SINAMICS Drive Selection and Dimensioning
- Enter the motor rating, supply voltage, load characteristics, duty cycle and control requirements.
- Select the suitable SINAMICS drive family and check communication options such as PROFINET or supported fieldbus interfaces.
- Add required operator panels, braking components, filters, reactors, cables and installation accessories.
- Review the generated drive-system data and confirm environmental derating, overload capability and motor compatibility.
Generate a Bill of Materials and Export to TIA Portal
Generate the Siemens Hardware Bill of Materials
After the configuration check returns no unresolved warnings, generate the product list or bill of materials. Review every MLFB order number, quantity, successor-product note, connector, BaseUnit, memory card, mounting accessory and power-supply item. A technically valid rack can still be incomplete for purchasing if installation accessories are missing, so compare the generated list with the electrical drawing and panel specification.
Transfer the Hardware Configuration to TIA Portal
Use the supported import/export workflow to transfer the validated hardware configuration between TIA Selection Tool and TIA Portal. The imported station pre-fills the device configuration with the selected CPU, modules and slot layout. Program blocks, tags, HMI screens and control logic are not created by this hardware transfer; they must still be engineered and downloaded in TIA Portal.
| Error / symptom | Likely cause | Fix |
|---|---|---|
| Module shows as incompatible (red highlight) | Module placed in an unsupported slot, or a firmware/order-number mismatch | Move the module to a supported slot, or check the required firmware version against what's selected |
| "Power budget exceeded" warning | The rack draws more current than the power supply can provide | Add a larger power supply, or split the rack across an additional segment |
| Import into TIA Portal fails | Exported file's TIA Portal version is newer than the version installed | Update TIA Portal, or re-export the station in a compatible version from TST |
| Item shown as unavailable or discontinued | Product has been replaced by a successor part | Apply the Siemens-suggested replacement shown next to the flagged item |
| Configuration not saving | Session expired, or not signed in to mySiemens | Sign back in to your mySiemens account and save the project again |
Step-by-Step Lab: Try It Yourself in TIA Selection Tool
Hands-on- Internet access and a free mySiemens account (or the offline TST app installed).
- A rough idea of the I/O count for a small demo panel — for example, 2 digital inputs and 1 analog output.
- No TIA Portal or hardware required for this lab; TST runs standalone.
- Estimated time: 10 minutes.
Create a project and add a CPU
Sign in to TIA Selection Tool and click Create new project > Add new station. Choose the SIMATIC S7-1500 family and drag a CPU onto the rack.
Add I/O modules and watch the power budget
Drag a digital input module and an analog output module into the next free slots. Keep an eye on the power budget bar as each module is added.
Trigger a compatibility warning on purpose
Try dragging a module from a different CPU family, or one that isn't rated for the slot type, into an occupied or unsupported slot. You can rehearse this first in the virtual rack above.
Fix the warning and export the configuration
Remove the incompatible module, click Check configuration, then generate the parts list and export the station.
If Step 3 showed a clear red warning and Step 4's "Check configuration" came back clean after you removed the conflicting module, you've correctly demonstrated the core value of TST: catching a hardware mistake on screen instead of discovering it after the parts arrive. Make "Check configuration" a standing habit before every export, not just this lab.
Frequently Asked Questions About TIA Selection Tool
What is Siemens TIA Selection Tool used for?
It is used to select and configure Siemens automation hardware, check supported combinations and power requirements, generate product lists, and transfer supported hardware configurations to or from TIA Portal.
Is TIA Selection Tool free?
Yes. Siemens provides cloud and desktop variants of TIA Selection Tool without a separate engineering licence fee.
What is the difference between TIA Selection Tool cloud and desktop?
The cloud version runs in a supported web browser and is convenient for shared or browser-based work. The desktop version runs on Windows, supports local project storage and is useful when offline access is required.
Can I configure S7-1200, S7-1500 and ET 200SP?
Yes. You can select supported CPUs, local modules, communication options and distributed I/O components, then validate the station configuration before generating the product list.
Can TIA Selection Tool help select HMI and SINAMICS drives?
Yes. The available configurators can support Siemens visualization product selection and SINAMICS drive-system dimensioning. Final options depend on the current product catalog, region and selected application data.
Can I export a TIA Selection Tool project to TIA Portal?
Yes. Supported hardware configurations can be transferred between TIA Selection Tool and TIA Portal. The transfer covers hardware configuration data, not PLC program logic or HMI application screens.
Does TIA Selection Tool generate a bill of materials?
Yes. It can generate a product or parts list containing the selected order numbers and quantities. Review accessories, connectors, BaseUnits, memory media and successor-product notes before ordering.
How do I read a Siemens 6ES7 order number?
Split it into blocks. 6ES7 is the SIMATIC S7 product group. The next three digits give the family (5 = S7-1500, 1 = ET 200 distributed I/O, 2 = S7-1200, 3 = S7-300, 4 = S7-400), the module type (0 = power supply, 1 = CPU, 2 = digital, 3 = analog, 4 = communication, 5 = technology, 9 = accessory) and the sub-type (for digital modules 1 = DI, 2 = DQ, 3 = DI/DQ). After the dash come the design digit, a version letter, a size or channel letter, the product version and the delivery version.
What does 6ES7 521-1BH00-0AB0 mean?
It is an S7-1500 digital input module, DI 16 x 24 V DC HF. 5 = S7-1500, 2 = digital module, 1 = digital input, B = 24 V DC version, H = 16 channels, 00 = product version and 0AB0 = delivery version.
What are the main module types in a Siemens S7-1500 PLC?
A typical S7-1500 station has a PM load power supply on the left (no slot), an optional system power supply (PS) in slot 0, the CPU in slot 1, and up to 30 modules from slot 2 to slot 31: digital input, digital output, analog input, analog output, communication (CM/CP) and technology (TM) modules. The CPU also needs a SIMATIC Memory Card, and each I/O module needs a front connector.
Why does an S7-1500 I/O module need a front connector?
S7-1500 digital, analog and technology modules are delivered without the wiring connector. The field wiring goes to a separate front connector, for example 6ES7 592-1AM00-0XB0 (40-pin, screw type, for 35 mm modules), which plugs into the front of the module. Make sure one front connector per module is on the parts list from TIA Selection Tool.
What is an MLFB number?
MLFB is Siemens's machine-readable product designation or order number. It identifies the exact hardware variant and is useful for verifying modules, spare parts and purchasing data.