من منتديات شركة سيمنس (( سؤال وجواب ))

The value 27648 has simply been selected as the maximum normal range value of any analog signal transfered to the CPU by a Siemens analog module.This numerical value is independant of the resolution of the particular analog module used (this is a way to standardize all scaling of analog readings in the processor)
For unipolar data, this would mean 0 to 27648 represents full range; above 27648, overrange, below 0, underrange.See the attached illustration for the equivalent numeric values iof a 4-20 mA or 0-20 mA signal.
The basic configuration of the analog modules is best explained in the S7-300 module Data manual:
http://support.automation.siemens.com/WW/view/en/8859629
Look at the chapters on Principles of Analog value processing and Representation of the analog values of analog modules

I don't know why you would wonder for so long about how a system was "derived".
As I said before, I believe a system was designed, and values selected.
The closest explanation I can find, if you examine the table I proposed earlier, and others in the Module Data manual, is that:

27648/32767= 0.839....
32512/32767= 0.992...

So this allows about 85% of the full range for the rated range values, a zone between 85% and 99% for overrange, and above 99% for overflow values.
Also, 27648 = hex(6C00) and 32512=hex(7F00); possibly the "00" ending of the hex values can be used easily as markers in their math calculations and compares. We did this alot when programming microcontrollers, in the past

the value 27648 is a digital value which representing the phyisical analog value. If you have a pressure transducer (4-20mA) and you will connect it to an AI. How the CPU sence the pressure. The changes in the pysical value (pressure) affect the electrical analog signal (4-20mA) and that happens inside the transducer. Then the changes of analog signal (4-20mA) is to be translated into digital values using the ADC "Analog to digital converter (0-27648). And that happens inside the Analog module. Then this value; the digital value is transferred to the CPU.
The reverse of the above senario is applied with Analog Outputs.

Siemens have also something important called the resolution of the analog channel ( min. 8 bits and max. 15bits)
The resolution is a factor when increase, then the precision increased. Thus because if you have 15-bit resolution AI module. for a very small changes in physical values, the CPU can mesure and sense that changes [i.e it would be able to measure (1/27648)*20mA.].
For 8-bit resolution; it would be able to measure (8/27648)*20mA.

I hope the above summary was useful for you to understand how the analog signals been read or written.

Also see the attachments and I am sure you will found in it more info

Basically for all questions, "hardware configuration logic" will helps. I mean in hardware configuration window-into the rack if you select some hardware which is not possible to put in this slot, you'll receive message).

3. Deppends what kind of application you have. Basically you can devide or not.

5. In S7-300 family doesn't exist this kind of module

in the manual for every module you can find the information where it can be used (or where it can't), also you could check the module description manual for S7-300 here.
(ad 5. you can use the Dummy module and the S7-300 rack with integrated bus for ET200M:

Unhappily the CPU 313C count up to 30 kHz.

If you need count up 100 kHz, I suggest you use a FM 350-1 (200 kHz).

About the usage of counter functions, you can have a good idea if you see the manual: S7-300 Automation System CPU 31xC Technological Functions - Link

S7-300 CPU 31xC Technological Functions

See chapter 1 (overview) and 5 (Counting, Frequency Measurement and Pulse Width Modulation).

If you wrote in VAT, PQW300 for instance, you will not able to monitor this value.
You can move it to memory area and then monitor it.

To avoid this method, you can go to HW config, change the addresses of analog outputs to be inside the process image of the CPU. For example; PQW 300 became PQW 30. and then go back to VAT and write QW30
Note I have eleminated here the letter "P"

Then you will be able to monitor it

1 - go online, select all blocks, press del , this will erase all but system blocks and data
1a - mark the blocks folder and klick on download , overwrite system data!

Remove the MMC card do mem reset and configure the ethernet. Upload your Rack an then your program.
When i have trouble sometimes is the best way because you have the warranty that you are starting from 0.

If you want to display temperature on HMI then the best way to do is to use one decimal point and no of digit can be decided by min and max range.

If your temp range is 0.0 to 150 deg C then format you can use is 999.9

Normally if you have RTD as analog input for temperature then you may need to divide the PIW256 by 10.0 to get exact temperature. But you have to convert the PIW integer to DI and then DI to Real, then divide the Real value by 10.0 you will get the result as real value.

Or you can use FC105 SCALE fuction from Siemens Standard library to scale & convert Integer to Real value. Here you need to put min and max temperature range to get correct result. Min is min temperature the sensor can sense and max is the max temp the sensor can sense.

When you have Protool v6 + sp1a, you can order Service pack 3 for free. See following link

http://support.automation.siemens.com/WW/view/en/19962184

I know two alternatives:

1 – Use M7
but is not more available
see Update http://support.automation.siemens.com/WW/view/en/14044569

2 – Use a PC + C program + WinAC - only as input / output interface

For programming an S7 controller you can't use C or C++ directly.

You can use the programming language S7-SCL, which is an high-level programming language for S7 controllers (similar to PASCAL). S7-SCL can be used for all nearly S7 controllers.

The other way (mentioned above) is to use WinAC (a software S7 controller, which is running on a PC) together with WinAC ODK. Have a look at the A&D Mall (https://mall.automation.siemens.com/) for a detailled description of WinAC ODK.

Here is an example for using the WinAC ODK:
: http://support.automation.siemens.com/WW/view/en/21572937Linking Windows Applications to WinAC RTX with WinAC ODK

Is easier to program in ladder.
I learned in one week. Know this OB 1 is your function main, Ob100 is the restart function, OB 35 is your cyclic function. OB82 is your hardware interrupt;
Procedures is your FC;
Functions is your FB associated to your DB (declaration of variables);
Then rock on.

Together with the FM configuration package there will be installed some examples

You can start with SIMATIC FM 350-1 First Steps in Commissioning

http://support.automation.siemens.com/WW/llisapi.dll/csfetch/2746047/get3501_e.pdf

Follow instruction from this manual you'll need from Configuration Package for FM 350-1 and FM 450-1 Counter Modules

http://support.automation.siemens.com/WW/llisapi.dll/csfetch/28291262/FMx50-1_V601.exe
http://support.automation.siemens.com/WW/llisapi.dll/csfetch/28291262/FMx50-1_V60.exe
http://support.automation.siemens.com/WW/llisapi.dll/csfetch/28291262/FMx50-1_V51.exe
http://support.automation.siemens.com/WW/llisapi.dll/csfetch/28291262/FMx50-1_V50.exe

After installing and connecting the sensor, you need only to create logic in Step7
Perhaps this manual also is usefull SIMATIC FM 350-1 Function Module

http://support.automation.siemens.com/WW/llisapi.dll/csfetch/1086726/s7300_fm350_1_manual_en_en-US.pdf

The following brochure from Siemens A&D explains the different families of ET 200 compact slaves available
https://www.automation.siemens.com/salesmaterial-as/brochure/en/brochure_simatic-et200_en.pdf
Hope this helps

ET200L
ET 200L is a small, compact I/O device with degree of protection IP20.

The ET 200L is mainly used for applications in the low-end performance range which require few inputs/outputs as well as for applications where space is limited.

The ET 200L is a passive node (slave) on PROFIBUS DP with transmission rates up to 1.5 Mbit/s.


ET 200S
The SIMATIC ET 200S is a distributed I/O system to IP 20 degree of protection. It comprises:
Interface module with PROFIBUS (alternatively with integral CPU) or PROFInet interface
Input/output modules
Technology modules
Frequency converters and motor starters for three-phase loads

Its extensive module spectrum and system-wide handling of configuring, installing and programming tasks make the ET 200S well-suited as a universal I/O system.

The discretely modular design ensures fast and optimum adaptation to system requirements:
No need to keep spares
No superfluous channels

Even when requirements change frequently, replacement or combining of different I/O modules can noticeably reduce setting-up times.

With a data signaling rate of up to 12 Mbit/s on the PROFIBUS DP and extremely powerful internal data transport capabilities, the ET 200S is also eminently suitable for extremely time-critical applications.

Two different versions are available for integrating safety technology with ET 200S.
With conventional wiring, SIGUARD components achieve Safety Category 4 according to EN 954-1 with motor starter applications
PROFIsafe components replace the wiring-based safety logic with a freely-programmable controller. This has the following advantages for the customer:
programming in the familiar STEP 7 programming environment in the LAD and FBD languages;
no separate tool is required for programming or configuration
the safety program executes in the same controller as the standard program;
a separate controller is not required
safety-related data can be transferred over the same fieldbus cable as standard data;
no additional wiring of the safety-related inputs and outputs is necessary
safety-related inputs and outputs can be combined with standard inputs and outputs within a DP station;
no additional safety-related DP nodes (stations) are necessary

The design of the ET 200S allows it to be used in areas subject to increased mechanical stress.

The system characteristics meet high plant availability requirements