Its VISIO.

Print screen from Simulink might be a fast solution!

I think MATLAB could help u in a greater extent in this case

I use Visio as well for its ease and ability to seamlessly integrate with Office products.

If that is just for drawing, I think ms visio will be more than enough, but if you need to simulate, I think Simulink MATLAB is the good choice

If it's a diagram of an actual model then Simulink (but don't Print Screen - under one of the menus there is an option to copy diagram that can then be pasted into WORD) - watch font size and line thickness. For drawing I would use Inkscape (free vector graphics drawing program) and save as PNG (for WORD) or EPS (for LaTeX).

Vote for MS Visio (because of its vector capabilities) and Matlab/Simulink.

can use SmartDraw

For some simple diagrams, TaxCAD is another choice.

The beauty of Visio is it is usually bundled in Office and there isnt a need to buy a program. There are many good templates to work with as well.

I would like to recommend Xfig. Xfig is free software, enough to drawing performance except color gradation tool. It runs Linux, cygwin (MS Windows) etc. Please try it.

Omnigraffle!

I will recommand Simulink (Matlab)

Vissim from Visual solutions

I have used Tikz for drawing control block diagram in my thesis. The quality is very good, but takes time to learn as compared with other softwares.

Visio is also very good. Inkscape is also suitable for drawing which is open source.

Try with MS VISIO, which gives clarity of the diagram even the size is adjusted to fit in your thesis appropriately

You can use either Simulink or MS Office Visio. Simulink provides with with all scientific notations and symbol whereas MS Office Visio is generic.

VISIO 2010 and SMARTDRAW. The latter allows page size to automatically increase and you do not have problems with font scaling that VISIO has when cut and pasting. Has a great set of STD engineering libraries . Can also do PPT presentations etc. You can download and try for free.

Visio 2010

You can use Matlab

I think Microsoft Vision 2007 is quite simple and easy to use

I am using both (i.e. Matlab and Visio).

I use all three Matlab(Simulink), Visio(2007) and Smart Draw. I think in the same order is the quality of control diagrams.

I have a side question for people using MS Visio: which templates/stencils/shapes do you use for this purpose? As far as I can see the standard Visio doesn't include any simulink-like resources.

I use Matlab(Simulink) and Visio(2013) then i use photoshop to increase the resolution.

Autocad electrical is also a good option! You can draw vector graphic symbols and objects. Also more professional drawing tools with respect to ms viso and smartdraw are available!

For me I use the MSW or sometimes MS Visio and is widely enough

But,

The thing that gives importance to your thesis is the continuous scientific, so do not waste a lot of time looking for aesthetics and focused on its scientific quality.

some Companies have their own drawing tools for example cisco use some symbols and blocks in their training course are not available in ms visio! any one knows which drawing tools are used for networking?

Microsoft office visio 2007

I am actually using IPE draw. Works nicely with latex word processing.

You can simply use MS power point as most control block diagrams are not as complicated as plant drawings. If the control diagram has more components or blocks with a lot of signals in-out, use MS visio will do. Most important thing is to have good scientific contributions and drawings are only secondary - sufficient that they are visually clear.

Inkscape for 2D and Blender for 3D pictures.

Blender for animations

For instance: https://www.youtube.com/watch?v=RasemoYzsFA

I just use AutoCad to draw it. Then I export it to PDF with high quality, and import to Photoshop to modify the size to the image. The image has quite good quality and fits well with the manuscript. Especially when we need detailed diagram.

Dear @Adolfo, have you completed your Ph.D thesis till now?

corelDraw

In my thesis, I used Microsoft Visio, but in several other situations I used the famous "Paint" or "Paintbrush" (that has been included with all versions of Microsoft Windows) for its simplicity, availability on almost any computer. It seems like a poor solution, but I work on it at a high speed and with surprising results.

Try https://www.draw.io/

Very neat.

LaTex is a good option

I use Latex.

Aman Jacknoon How do you use Latex, can you give some explanation or source as example?

use Microsoft Visio

Jorge Ignacio Cisneros-Saldana Overleaf provides an example here

https://www.overleaf.com/latex/examples/control-block-diagram-with-tikz/jfdcfxhgjmtz

Lucidchart is a visual workspace that combines diagramming, data visualization, and collaboration to accelerate understanding and drive innovation...

https://www.lucidchart.com/pages/landing/engineering/block-diagram-examples?utm_source=google&utm_medium=cpc&utm_campaign=en_tier3_desktop_nb_x_bmm&km_CPC_CampaignId=2083917352&km_CPC_AdGroupID=82392365728&km_CPC_Keyword=%2Bblock%20%2Bdiagram%20%2Bsoftware&km_CPC_MatchType=b&km_CPC_ExtensionID=&km_CPC_Network=g&km_CPC_AdPosition=&km_CPC_Creative=432945663098&km_CPC_TargetID=kwd-310332632328&km_CPC_Country=21213&km_CPC_Device=c&km_CPC_placement=&km_CPC_target=&mkwid=sZaXigHXH_pcrid_432945663098_pkw_%2Bblock%20%2Bdiagram%20%2Bsoftware_pmt_b_pdv_c_slid__pgrid_82392365728_ptaid_kwd-310332632328_&gclid=CjwKCAjwtqj2BRBYEiwAqfzurwA1rGoCnEo5V0c33Qg4cSzC-euDOwonmvcjVYhgZmRAw2VqwSaIEhoCBmoQAvD_BwE

Overleaf

Microsoft Visio and Corel draw

EPLAN?

Many cooleagues use DiaPortable.

https://portableapps.com/apps/office/dia_portable

Dear Adolfo Silva

A block diagram is a diagram of a system in which the principal parts or functions are represented by blocks connected by lines that show the relationships of the blocks.

The best software to draw control block diagram : Microsoft Visio or Corel draw

Tableau Desktop is also good one for drawing the scientific illustrations.

https://www.diagrameditor.com/

Tikz, which utilizes Latex, is a great tool to draw control diagrams. Please check the following link for excellent tutorials:

https://latexdraw.com/block-diagram-in-latex-step-by-step-tikz-tutorial/

You can use Simulink, then save a simulink file as an image

I recommend you "SmartDraw", Good luck