PLC programming · Free

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers

What the S7-1500 does between your rungs: OB1 and the cycle, OB100 at startup, time-delay, cyclic and hardware interrupts, the error OBs that keep a CPU out of STOP, time of day, and every timer the instruction tree offers.

8 modules 3h 48m of video English · self-paced

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers course cover

Inside the course

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers: Syllabus at a glance

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers: What you will be able to do

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers: Tools and credits

From the lessons

OB1, the Cycle and Cycle Time; OB100 at Startup
Hegamurl
Time-Delay Interrupts (OB20) and Cyclic Interrupts (OB30)
Hegamurl
Hardware Interrupts (OB40): Digital and Analog
Hegamurl
Error OBs: OB80 Time Error, OB82 Diagnostic Error and OB121 Programming Error
Hegamurl
System Time, Local Time and Time-of-Day Interrupts (OB10)
Hegamurl
Timer Types, TON, TOF, TP and TONR, Reset and Preset
Hegamurl

Lesson frames belong to the creators named in the Credits below and are shown from YouTube.

What you will learn

Explain the S7-1200/1500 cycle and read its cycle time, use OB100 for startup work, write time-delay, cyclic and hardware interrupt OBs, handle time errors, diagnostic errors and programming errors in OB80, OB82 and OB121, work with system and local time, and use TON, TOF, TP, TONR, legacy timers and clock memory correctly.

Read and change the cycle time and use OB1 correctly
Do startup work in OB100 such as counting restarts
Write OB20 time-delay and OB30 cyclic interrupts
React to digital and analog hardware interrupts in OB40
Keep a CPU running with OB80, OB82 and OB121
Use every timer type, reset and preset them, and use clock memory

For you

Taking Siemens TIA Portal: Organisation Blocks, Interrupts and Timers from the United States

Free in the United States, as everywhere, and self-paced: lessons, notes and the final assessment are open at any hour, so your time zone and shift pattern do not matter.
The optional certificate for learners in the United States is a one-off US$28.99. What you get for it
Siemens is one of the automation brands most widely installed across the Americas, so this is a skill plants and integrators near you ask for.
See automation and engineering jobs in the United States, and what the industry looks like in Houston, Detroit and Chicago.
EDWartens also has a regional site for the United States, for classroom training and local support: edwartens.com/us.

The course project · about 16 hours

Stamping press production control: stroke counting in OB40, cushion watch in OB30, shift changeover in OB10

Design, program, test and document the production-control PLC for a 250-tonne mechanical press: exact stroke counting from a crank proximity sensor in a hardware-interrupt OB, a 20 ms cyclic interrupt that watches die-cushion pressure, a time-of-day interrupt that closes the shift totals, lubrication and cushion timing with TON, TOF, TP and TONR, and error OBs that log a broken analog wire instead of stopping the CPU. You deliver the program, your own I/O list and FAT record, and the software design specification that explains every OB. The sample pack shows what an integrator delivers for the same press.

Sample document pack, 8 documents, filled in for the scenario

Control narrativeControl Narrative: Press PR-3 Production Control
SDSSoftware Design Specification: Press PR-3 Production Control
I/O listI/O List: Panel CP-31
BOMBill of Materials: Panel CP-31 and Field Instruments
Alarm listAlarm List: Press PR-3
Interlock listInterlock and Permissive List: Press PR-3
FATFactory Acceptance Test Record: Panel CP-31
O&M manualOperation and Maintenance Manual: Press PR-3 Production Control (Operation section)

Read inside the course and download as a workbook. The project is optional practice, marked when you submit it; the certificate needs only the modules and the final assessment.

Course content

8 modules · 20 lessons · 3h 48m

In order, at whatever pace suits you. Each module ends with a practice task that builds on the last.

01OB1, the Cycle and Cycle Time; OB100 at Startup2 lessons18m
02Time-Delay Interrupts (OB20) and Cyclic Interrupts (OB30)2 lessons26m
03Hardware Interrupts (OB40): Digital and Analog2 lessons21m
04Error OBs: OB80 Time Error, OB82 Diagnostic Error and OB121 Programming Error4 lessons56m
05System Time, Local Time and Time-of-Day Interrupts (OB10)3 lessons28m
06Timer Types, TON, TOF, TP and TONR, Reset and Preset3 lessons41m
07Legacy S7 Timers, Clock Memory and Counting Seconds3 lessons38m
08Final Assessment1 lesson10m

Requirements

Who it is for: Intermediate. You should already write ladder in TIA Portal.
Software: TIA Portal V15 or later (21-day trial) with S7-PLCSIM What to download, and how
Hardware: None, everything runs in simulation

Software you need

What to download, where from, what it costs and how to install it. Every link goes to the maker's own site, never a mirror.

Required

01
SIMATIC STEP 7 Professional and WinCC (TIA Portal) V21 Trial
Siemens
Free trial: 21 days
Runs on
Windows 11 Pro or Enterprise 64-bit (24H2), Windows 10 Enterprise 2021 LTSC, or Windows Server 2022/2025. Windows 11 Home is supported only for the Basic editions.
Account
A free Siemens account registered for Industry Online Support (SiePortal)
Size
about 8.1 GB for the main ISO, plus an optional 3.1 GB DVD 2 with hardware support packages
Siemens lets registered users download the V21 trial of STEP 7 (Basic and Professional), STEP 7 Safety and WinCC and test it for 21 days. The same package is used for the full product; after 21 days you need a purchased licence to keep working.
Show the 6 stepsHide the steps
Steps
1. 1.Open the Siemens trial page (entry 109989774) and sign in with your Siemens Industry Online Support account.
2. 2.Download TIA_Portal_STEP7_Safety_WinCC_V21.iso (8.1 GB).
3. 3.Download S7-PLCSIM_V21.iso (2.5 GB) from the same page: PLCSIM is a separate download.
4. 4.Right-click each ISO, choose Mount, and run Start.exe as administrator. Install STEP 7 and WinCC first, then PLCSIM.
5. 5.Follow the setup, accept the licence terms and restart the PC when asked.
6. 6.Open TIA Portal V21 and create a new project to confirm it runs.
- Install from a local drive with plenty of free space; Siemens lists 20 GB free as the minimum and the ISOs alone are over 10 GB.
- You only need DVD 2 if you want extra hardware support packages.
- If you cannot install locally, Siemens also offers a 21-day TIA Portal Cloud trial in the browser (one-hour sessions, not in every country).
Official download pagesupport.industry.siemens.com
Alternatives
- TIA Portal Cloud trial: 21 days free in a cloud virtual machine, no install. Sessions are limited to one hour and it is not available in every country.
02
S7-PLCSIM V21 (TIA Portal) Trial
Siemens
Free trial: 21 days
Runs on
Windows 11 Pro or Enterprise 64-bit (24H2), Windows 10 Enterprise 2021 LTSC, or Windows Server 2022/2025. Windows 11 Home is supported only for the Basic editions.
Account
A free Siemens account registered for Industry Online Support (SiePortal)
Size
about 2.5 GB (ISO)
S7-PLCSIM V21 is offered as a 21-day trial on the same Siemens page as the STEP 7 and WinCC V21 trial. It needs STEP 7 V21 installed on the same PC.
Show the 5 stepsHide the steps
Steps
1. 1.Open the Siemens STEP 7 and WinCC V21 trial page (entry 109989774) and sign in.
2. 2.Install STEP 7 V21 from the main TIA Portal ISO first.
3. 3.Download S7-PLCSIM_V21.iso (2.5 GB) from the section Download S7-PLCSIM Standard V21.
4. 4.Mount the ISO, run Start.exe as administrator and follow the setup.
5. 5.In TIA Portal, select your CPU and click Start simulation to open PLCSIM.
- Siemens notes that the PLCSIM Standard V21 installation also includes S7-PLCSIM Advanced V8.0.
Official download pagesupport.industry.siemens.com

Checked against each maker's own page on 27 September 2026. Trial lengths and editions change; the maker's page is the final word.

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers at a glance

Siemens TIA Portal: Organisation Blocks, Interrupts and Timers is a free, self-paced online course from EDWartens for engineering students, ITI and diploma holders, and working engineers in automation, electrical and instrumentation. It has 8 modules and 3h 48m of video lessons by Hegamurl, with written notes and worked problems, a practical project with a document pack and a 15-question final assessment (pass mark 60%). Learning is free with an account; an optional certificate with a public verification code is issued when you pass. Last updated 27 September 2026.

All course facts

Price: Free, for good. No trial, no card. The only paid item is the optional certificate, a small one-off fee.
Who it is for: Engineering students, ITI and diploma holders, and working engineers in automation, electrical and instrumentation
Format: 8 self-paced modules, 3h 48m of video, written notes, a practice task per module and one final assessment.
Level: Intermediate. Intermediate. You should already write ladder in TIA Portal.
Brand: Siemens
Software: TIA Portal V15 or later (21-day trial) with S7-PLCSIM
Hardware: None, everything runs in simulation
Certificate: Optional EDWartens Certificate of Completion, verifiable by code. Not a vendor credential.
Video lessons by: Hegamurl (independent creators, credited below)
Language: English
Last updated: 27 September 2026

A shareable EDWartens certificate

Finish every module and pass the final assessment, and the optional EDWartens certificate is yours. It carries a unique verification code on a public page anyone can check, so it stands up when a recruiter looks it up. See it below.

Add it to your LinkedIn profile in one click
Link it from a CV or portfolio, the URL is permanent
Publicly verifiable by code, not a PDF anyone can edit
Issued by EDWartens itself, not a third party

The course itself stays free whether or not you ever buy one.

Stuck? Ask a practising engineer

A free course usually means a comment section and hope. This one does not. Every module has an Ask-your-trainer panel that reaches the same engineers who teach our paid programme: people who commission panels for a living, not moderators.

Questions answered in the context of the module you are on
The same engineers who teach the AEP programme
Career tools, CV help and public job listings included
Your progress and notes stay in your account for good

Pairs well with

PLC programming · FreeSiemens TIA PortalFrom zero electrical knowledge to a working, simulated S7-1200 program, for nothing.

Siemens TIA Portal in Three Hours free course cover

PLC programming · FreeSiemens TIA Portal in Three HoursThe first three hours of the Siemens TIA Portal course, cut to end on a win: what a PLC is, how it is wired, a project configured in TIA Portal, and your first ladder program running in simulation. Finish it in an evening or two, earn a certificate, and carry straight on into the full course.

TIA Portal: Build a Machine free course cover

PLC programming · FreeTIA Portal: Build a MachineOne machine, start to finish. Take a bottle filling line from a written specification and an I/O list to a structured S7-1200 program with a fill station, a capper, a reject sorter and an operator screen with alarms, then test it against a written record and archive it for hand-over. The lessons are the reference; the machine is yours, and it is what you submit.

Siemens S7-1200 with TIA Portal: The Tutorial Series free course cover

PLC programming · FreeSiemens S7-1200 with TIA Portal: The Tutorial SeriesEvery S7-1200 instruction, one short video at a time: bits, edges, timers, counters, comparators, maths, MOVE, conversion, analog scaling, jumps and shift registers.

More free courses: Free Siemens PLC courses · Free PLC programming courses

Learning paths with this course

Siemens engineer path · 13 coursesThe Siemens stack most plants actually run: TIA Portal from zero, the S7-1200 instruction series, program structure, HMI panels, interrupts, PID, commissioning, Factory I/O projects, the S7-300 installed base, advanced S7-1500, safety, WinCC SCADA and LOGO!.

Learner reviews

No reviews yet

Reviews here are written only by learners who have finished every module of Siemens TIA Portal: Organisation Blocks, Interrupts and Timers, and they are published exactly as written. Finish the course and yours will be the first.

Common questions

Is this only for the S7-1500?

The OBs and timers are the same on the S7-1200 and S7-1500; a few diagnostics are richer on the 1500. Everything is shown in PLCSIM.

Why do I need error OBs?

Without them a diagnostic or programming error puts the CPU into STOP and the line stops with it. With them the fault is logged and the CPU keeps running.

Is the Siemens TIA Portal course really free?

Yes. Every module, practice task and assessment. You create an account so your progress is saved and the assessments can be marked. The certificate is the only paid item, and only if you want it.

What certificate do I get, and is it a Siemens qualification?

An EDWartens Certificate of Completion, issued when you pass the final assessment, with a verification code anyone can check. It is not a Siemens credential and is never described as one.

Who made the video lessons in the Siemens TIA Portal course?

The creators named in the Credits block at the foot of this page, on their own YouTube channels. EDWartens did not make the videos and the creators are not affiliated with EDWartens. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.

How long does the Siemens TIA Portal course take?

Plan on about 6 hours in all, including the video lessons, notes and practice tasks. It is self-paced, so you work through the eight modules at your own speed.

Do I need a real PLC?

No. Everything runs in TIA Portal with S7-PLCSIM, which you can use on Siemens' 21-day trial.

What you walk away with

Your certificate for Siemens TIA Portal: Organisation Blocks, Interrupts and Timers

Finish the course, pass the final, and this is the document with your name on it.

Sample EDWartens Certificate of Completion for Siemens TIA Portal: Organisation Blocks, Interrupts and Timers — Sample. The issued certificate carries your name, admission number, a unique certificate number and its own QR code.

Verifiable by anyone
A unique certificate number and a public verification page. A recruiter checks it in ten seconds.
Adds to LinkedIn in one click
Issuer, credential ID and URL prefilled, with 6 matching skills to pin to your profile.
QR code on the certificate
Scans straight to the verification page, so a printed copy proves itself.
Names what you can do
Lists the topics covered, from ob1, the cycle and cycle time; ob100 startup to timers ton, tof, tp, tonr, legacy timers and clock memory.
A permanent link
Put it on a CV, a portfolio or an application. The URL never changes.
Earned, not attended
Issued only after every module and a final assessment at 60%, with 3 attempts. That is why it stands up.

Learning is free. The certificate is optional.

Add it now and pay only when you have finished the course, or come back for it later. One-off, US$28.99, with a receipt.

Issued by EDWartens, the training division of Wartens, as a Certificate of Completion for this self-paced course. Sold by Wartens Ltd (England and Wales). It is not a vendor certification, a university award or a CPD-accredited activity, and it does not certify competence on live equipment. Delivered electronically; see the refund policy.

Credits

Who made the video lessons

The video lessons in this course were created by the people below, not by EDWartens. Every lesson streams from its creator's own YouTube channel; EDWartens neither hosts nor sells that footage, and the creators are not affiliated with EDWartens and do not endorse this course. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.

Hegamurlthe TIA Portal interrupts and organisation block series
Hegamurlthe TIA Portal timer series

If you are one of these creators and would like a lesson removed or credited differently, write to info@wartens.com.