Description
In STEP 7 (TIA Portal) V11 you cannot download a project into an S7-1200 CPU when you have previously downloaded with STEP 7 V12. The download procedure is aborted with an internal system error.

Remedy
Beforehand you must reset the S7-1200 CPU with STEP 7 (TIA Portal) V12 to the factory settings.

To reset the S7-1200 CPU to the factory settings you remove the memory card and put the CPU into STOP mode.

1. In the project navigation you open "Online & Diagnostics" function.
2. In the "Functions" folder you click "Reset to factory settings".

Fig. 01

3. In the dialog that opens you can choose whether you want to retain or delete the IP address. Click the "Reset" button and answer the subsequent security query with OK.
4. You can then use STEP 7 (TIA Portal) V11 to download the project into the S7-1200 CPU.

Fig. 02

More information is available in the STEP 7 (TIA Portal) V12 Online Help under "Resetting a CPU to factory settings".

Note
If you do not reset to factory settings, the download procedure in STEP 7 (TIA Portal) V11 aborts with an internal system error message. If the STEP 7 (TIA Portal) V12 software is not available in the case, you must reset the factory settings with a Siemens MCC.

Creation environment
The screens in this FAQ response were created with STEP 7 (TIA Portal) V12.

Additional Keywords
Version conflict

Description
In STEP 7 (TIA Portal) V12, if you use the spectacles symbol in the toolbar to disconnect an online connection, formerly a message appeared querying whether you want to disconnect the online connection. Only when you confirmed with "Yes" was the online connected disconnected. In order to prevent this message being displayed when changing to Offline mode you check the check box "Do not show this message again".

Fig. 01

This message then no longer appears when you want to disconnect the online connection, not even when you restart the TIA Portal and use a different or newly created project.

Remedy
Proceed as follows to re-enable this message:

1. Open the Explorer in MS Windows and navigate in the path below to the file "Settings.xml":

C:\Users\<UserName>\AppData\Roaming\Siemens\Automation\Portal V12\Settings
"UserName" stands for your own user name.

2. Change the name of the "Settings.xml" file to "Settingsold.xml".

Fig. 02

3. Close STEP 7 (TIA Portal) V12 and restart the tool.
4. Open a different or newly created project. After disconnecting the online connection using the spectacles symbol the message described above is displayed again.

Creation environment
The screens in this FAQ response were created with STEP 7 (TIA Portal) V12 and Windows 7.

Additional Keywords
Disabled system messages

Description
In a detailed comparison of the blocks inconsistencies might occur in the separate networks with the "Compare > Offline/Online" function in STEP 7 (TIA Portal) V11. This behavior occurs when you download your blocks in the CPU in the STL view, but execute the offline/online comparison in the LAD or FBD view.

Fig. 01

Fig. 01 shows the offline/online comparison of a function. For displaying in LAD and in FBD, the metadata required for these displays is missing in the online view. The networks in the offline and online views are identical semantically and differ only in the display.

Remedy
If you have created your program in the LAD or FBD programming language, do not make the download in STL. After renewed downloading in the LAD or FBD language the displays are once again identical in the offline/online comparison.

Creation environment
The screens in this FAQ response were created with STEP 7 V11.0+SP2.

Description
The "Compatibility Mode V11" must be opened if a program upload of a device configured with STEP 7 (TIA Portal) V11 (a SIMATIC controller or an SIMATIC HMI, for example) is to be made in STEP 7 (TIA Portal) V12. However, this is only possible if a STEP 7 (TIA Portal) V11 project is open.

For the case that you do not have a STEP 7 (TIA Portal) V11 project, we have included an empty STEP 7 (TIA Portal) V11 project for downloading in this FAQ response.

Download
The download contains the "compatibility_mode_V11_V12.zip" project.
Copy the "compatibility_mode_V11_V12.zip" file into a separate directory and then start the file with a double-click. You can then use STEP 7 to open and process the extracted project data.

compatibility_mode_V11_V12.zip ( 376 KB )

Creation environment
The download in this FAQ response was created with STEP 7 (TIA Portal) V11 SP2 Update 5.

Description
Changes to parameters marked as "retained" made with the editors of the technology objects do not affect the current parameters in CPU.

If only the PID parameters changed in the configuration mask are downloaded to the CPU, then:

• These values are written only to the load memory of the CPU.
• The current memory of the CPU is not updated with these values.
• An overall reset of the CPU must be made for these values to be transferred once to the current memory.

This behavior is an advantage for most applications, because the PID parameters of an automatic optimization are retained even if there is a power failure.

The table below gives a number of remedies for manual setting of the parameters.
 

No.	Workaround
1	Monitoring table Open a monitoring (watch) table and change the relevant parameters online. The new values are accepted immediately as current values and are thus active.
2	Download all blocks to the device Download not only the change to the software but also all the blocks to the CPU. In the project tree, you right-click the required CPU and select the "Download to device > Software (all blocks)" command in the pop-up menu. Fig. 01 Note This action causes all the software blocks to be downloaded to the CPU. This deletes all the retained data in the CPU!Data for the device configuration is not loaded.
3	Overall reset of the CPU before downloading Refer here to the information in the STEP 7 V11 Online Help under "Basic information for an overall reset". When you do an overall reset of the CPU it is reset to its factory settings and once the content of the main memory has been deleted, the data blocks no longer have a current value, but only their initial values.
4	Reset to factory settings Refer here to the information in the STEP 7 V11 Online Help under "How to reset a CPU to factory settings". In the project navigation of your selected CPU you open the PLC folder and double-click "Online & Diagnostics". From the three drop-down list boxes in the "Online Access" dialog you select the PG/PC interface and the connection to the subnetwork. Click "Go online" button. Fig. 02 When the online connection has been established, open the "Functions" folder. Select the "Reset to factory settings" function and click the "Reset" button in the right window. Before resetting you have the option of resetting the IP address. If you wish to retain the IP address, you must enable the "Keep IP address" option. Fig. 03 Note Using the "MRES" switch found on some CPU modules does not have any effect here. The retained data is not deleted.

Creation environment
The screens in this FAQ response were created with STEP 7 V11.0+SP2.

Additional Keywords
Retain parameters, TO editor, PID_Compact, PID_3Step, Controlling, Controller

Description
After establishing the online connection some blocks are marked differently in the project navigation and it is not possible to control the variables. However, the program code of the blocks in the CPU is identical to the configuration in the TIA Portal.

Fig. 01

When you execute the "Compare > Offline/Online" function, messages indicating that the code is different are displayed in the "Details" column for the symbolically marked blocks. However, no differences can be found in another code block comparison.

Reason
It is very probable that you have made changes in the marked blocks after the last download. Even if you have subsequently discarded the changes and your program corresponds to the original code contained in the CPU, the time stamps of the online and offline blocks are nevertheless different. Each time an online connection is established, a simple online-offline comparison is made and the blocks are marked with symbols in the project navigation. The result of this comparison depends on the time stamp.

Fig. 02 shows the "Properties" dialog for the "Test_Feb" function block. In the "Time stamps" tab you see the date entries for creation of the block and for the modifications made.

Fig. 02

The date of the last modification made to the block always corresponds to the time stamp of the interface or the code. And the time stamp of the code is updated each time the block code is modified, even if you have subsequently undone the modification. For example, when you add a statement and then remove it again.

Remedy
You must compile the program and load it into the CPU once again. Select the block container in the project navigation and then press the Download button. This downloads all the different blocks, identical blocks are not subsequently downloaded.

Alternatively, you can load separate components like the hardware configuration, changed or all the software blocks. If you right-click the folder in the project navigation, the following menu commands are offered in the pop-up menu:

• "Download to device > All"
  The project data (hardware configuration and the STEP 7 program) are loaded into the CPU.
  
• "Download to device > Hardware configuration"
  Only the hardware configuration is loaded into the CPU.
  
• "Download to device > Software"
  Only changed software blocks are loaded into the CPU.
  
• "Download to device > Software (all blocks)"
  All the software blocks are loaded into the CPU. Data for the device configuration is not loaded.

Fig. 03

More information is available in the STEP 7 V11 Online Help under

• Basics of project data comparison
• Time stamps of blocks

Creation environment
The screens in this FAQ response were created with STEP 7 V11.0+SP2.

Additional Keywords
Comparison symbols

Instructions
A comprehensive detailed description of how to create user-defined websites in STEP 7 (TIA Portal) is available in the Online Help. The essential information is available under the keywords below:

• Procedural overview
• Creating and loading a data block
• Creating web pages
• Definition of fragments
• WWW: Synchronize user-defined websites
• What you need to know about custom web pages

To enable access also with an iPad to the websites made available by the web server of the CPU you must insert a separate login form in the HTML pages. Fig. 01 shows an example of an HTML code.

Fig. 01

You can also incorporate the jQuery library in the website for simple and dynamic programming of the HTML pages. This is shown in the figure below.

Fig. 02

The jQuery library is a free, extensive JavaScript class library that provides convenient functions for DOM manipulation and navigation. This library can also be stored directly on the web server of the controller if there is no internet access, for example. In this case, the links to the storage path of jQuery on the web server are used in the HTML source text instead of the links to the internet site of jQuery.

You must then insert the line below in the jQuery library file:

<!-- AWP_Start_Fragment Name="jQuery1" -->

Then another line roughly in the middle of the file:

<!-- AWP_Start_Fragment Name="jQuery2" -->

These AWP commands split the file which would otherwise be to large to store in one data block. The jQuery library function is retained.

Fig. 03

Fig. 03 and Fig. 04 show access to the websites of the CPU using an iPad. Once you have logged in, the buttons for controlling a plant are made available.

Fig. 04

The table below describes how to proceed to incorporate a user-defined website for an S7-1200 CPU in order to use jQuery with an iPad.
 

No.	Procedure
1	Create the HTML file for your user-defined website. To use jQuery you incorporate the framework in the home page like any other external JavaScript file. For this you must integrate the JavaScript library in the header. You need an HTML editor that supports the jQuery library functions. The HTML file in this example was created with Dreamweaver CS5.5 from Adobe Systems and contains some notes on the jQuery syntax. Otherwise, extensive information in various languages is available in the internet under the keyword "jQuery", so we will not deal further with the syntax or handling of the functions in this entry. Note on STEP 7 (TIA Portal) V11 If you want to store the jQuery library on the controller, you must replace the character string "]]" with the character string "] ]" in the jQuery file; in other words insert a blank. Otherwise STEP 7 V11 issues a warning and the file is not integrated. From STEP 7 (TIA Portal) V12 it is no longer necessary to change the character string and you do not have to insert the AWP command. Download The download includes the PDF file with the HTML code for the website shown in Fig. 03 and Fig. 04 including the German and English comments. STEP7_V11_Userdefined_Webpage_for_iPad.pdf ( 25 KB ) Note The jQuery library is incorporated with a link in the page using the CDN method. The CDN (Content Distribution Network or Content Delivery Network) is a network of locally distributed servers linked over the internet used to deliver content (in particular large media files). The CDN nodes are distributed over many locations and are used to handle user requests for content as economically as possible.
2	Open the device configuration in your STEP 7 project for the CPU for which you wish to create the website and double-click the S7-1200 CPU module.
3	Select the "Properties" tab and mark the "Web server" folder in the area navigation. The Properties dialog for user-defined websites then opens.
4	Activate the "Enable web server on this module" option and acknowledge the security message with OK. Note The password mentioned above is defined in the CPU properties of the device configuration in the "Protection" tab. It is recommended to always use a password to prevent unauthorized access.
5	In the "HTML folder" field you enter the folder in which you have stored your HTML files.
6	Under "Start HTML Page" you enter the name of the HTML file to be opened first. For example, the file you created in Point 1.
7	Assign and application name and click the "Create data blocks" button. The data blocks created contain the metadata for the complete web application and are stored in the "System data blocks" folder in the project navigation.
8	Open the "Main [OB1]" block and you insert the "WWW" block in the network from the "Communication" palette and from the "Web server" folder.
9	Enter the number 333 (for DB333) at the "CTRL_DB" parameter and parameterize the "RET_VAL" with a variable of the Int data type for the error information. Fig. 05
10	Save and compile the project and download the program into the CPU.
11	Switch on the iPad and then swipe the onscreen arrow on the Slide to Unlock bar on the bottom of the screen. This unlocks the iPad.
12	In the main menu of the iPad you select the "Settings" dialog.
13	Press "Wi-Fi" and select your network.
14	Press the arrow button next to the network name and select the "Static" tab in the dialog that opens.
15	Enter an IP address for the iPad, for example: IP Address: 192.168.80.41 Subnet Mask: 255.255.255.0
16	Return to the main menu and press "Safari".
17	Now enter the IP address of the CPU in the address bar at the top. When you select the address bar, the virtual keyboard for entering the letters is displayed at the bottom of the iPad. Press the ".?123" button to enter numbers and special characters. Press the "ABC" button to return to letters.
18	In the navigation area you select "User pages" and the start the web site by clicking the application name. The application name is the name you assigned in Point 7.
19	In the main menu, press "Login" and in the dialog that opens you enter the user name and the password. Then click the "Login" button.
20	After logging in you have read and write rights to your inputs and outputs and you can control your plant.

Creation environment
The pictures and downloads in this FAQ response were created with STEP 7 V11+SP2.

Additional Keywords
DOM (Document Object Model)

Instructions
To load project data into the CPU you need an online connection between your programming device and the device or CPU. The table below describes a sample downloading process for an S7-1500 CPU (generally valid for all CPUs). Under circumstances it might be necessary to first reset the S7-1500 CPU to the factory settings if the module memory is not initialized automatically. Even if the configured CPU is identical to the available CPU, the device is displayed as "not compatible". The reason for the behavior is that the Primary Setup Tool, for example, or another tool was used instead of the TIA Portal to change the IP address from the as-delivered status of the CPU.
 

No.	Procedure
1	In the project navigation, you mark the folder (PLC_1, for example) whose project data you want to load into the CPU and then you execute the menu command "Online > Download to device" or click on the "Download to device" icon in the toolbar. The changed project data (device configuration and the STEP 7 program) are then loaded into the CPU. Fig. 01 Alternatively, you can load separate components like the hardware configuration and the software blocks. If you right-click the "PLC_1" folder in the project navigation, the following menu commands are offered in the pop-up menu: "Download to device > Hardware and Software (changes only)" The device configuration and the changed software blocks are loaded into the CPU. "Download to device > Hardware configuration" Only the hardware configuration is loaded into the CPU. "Download to device > Software (changes only)" Only changed software blocks are loaded into the CPU.
2	With the first download the "Extended download to device" dialog opens. Here you have to define your PG/PC interface. In the drop-down list boxes you select your configuration data and then click the "Load" button. Fig. 02 The IP address of your CPU configured in the device configuration must match the IP address of the CPU that is accessible online. Fig. 03 Note If you enable the option "Show All Compatible Nodes", all the accessible devices are shown with their IP addresses and you can load your program directly into the CPU without having to change the IP address of the module in the offline project.
3	The Ethernet interface of your programming device must be in the same IP band as the module to be configured. If an IP address has already been assigned for your PG/PC, you no longer get the dialog shown in Fig. 04. Click on the "Yes" button. Fig. 04 Also acknowledge the next message.
4	The project data must be consistent. If the project has not been compiled, the project data is compiled automatically before being loaded. In the "Load preview" dialog, messages are displayed and the actions required for loading are proposed. It is only necessary to stop the CPU if the device configuration is loaded or if you have changed the texts in the text lists. If you have loaded only blocks into the CPU, you do not need to put the module into "STOP" mode. In the "Text libraries" line (only with S7-1500) we recommend that you select the "Consistent loading" action. In this way all message texts and text list entries are loaded into the CPU. The "Load" button becomes active as soon as it is possible to load. Click the "Load" button. Fig. 05
5	At the end the "Results of the download procedure" dialog opens informing you whether the loading procedure was successful. Click the "Finish" button to put the CPU into "RUN" mode. Fig. 06 In the inspector window go to "General > Info" for detailed information about the load procedure.
6	After you have loaded the project data into the CPU and put the CPU back into "RUN" mode, you can execute the test and diagnostics functions on your CPU.

Table 01

Note on downloading an earlier version of STEP 7 TIA Portal (S7-1200 CPU)
If you have loaded a project with STEP 7 TIA Portal V12 (or higher) into an S7-1200 CPU and would then like to make more downloads with an earlier version of STEP 7 (V11, for example), you have to reset the CPU to the factory settings. You can do this either with the current version of STEP 7 TIA Portal or with a Micro Memory Card.

Note on S7 routing to an HMI device (S7-1500)
The S7 routing to an HMI device cannot be executed if the option "Use different method to assign IP address" is enabled in the Properties of the CPU S7-1500 (Fig. 03). Connect the HMI device over the second PROFINET interface [X2], because a fixed IP address point is needed from the STEP 7 project for S7 routing.

Further Information
More information is also available in the STEP 7 TIA Portal Online Help under "Download into CPU".

Creation environment
The screens in this FAQ response were created with STEP 7 (TIA Portal) V12.

Downloading from a project into the CPU
Using the two menu commands given below, in STEP 7 (TIA Portal) V11 you can download the complete project data into a module of your choice:

• "Online > Download to device"
  Loads the compiled hardware and software project data into the selected device.
• "Online > Extended download to device..."
  Establishes an online connection to the device selected and downloads the compiled hardware and software project data into the CPU.

Uploading from the CPU into a project
The table below explains how you can upload blocks from the CPU into the PG, for example, into a newly created project.
 

No.	Procedure
1	In order to upload all the blocks in the CPU (OBs, FBs, FCs, DBs) and the global variables into your project, select the menu command "Online > Accessible Devices...". Fig. 01
2	After the online connection has been established, in the "Accessible devices" dialog, you click the "Show" button. The accessible device with the "Program blocks" folder is then displayed in the project tree under "Online access". Note The accessible device must be displayed and be accessible. If your programming device and the CPU are not connected via the Industrial Ethernet interface, the button described above is grayed out.
3	Right-click on the "Program blocks" folder of the accessible device and select the "Copy" function in the pop-up menu. Fig. 02
4	Then right-click the upper "Program blocks" folder of your new project and select "Paste" in the pop-up menu that opens.
5	In the dialog that opens you activate the "Continue" action to enable the "Upload from device" function. Fig. 03 Now you click the "Upload from device" button. The program blocks are then transferred into the new project.

Creation environment
The screens in this FAQ were created with STEP 7 (TIA Portal) V11.

Instructions
If you remove the memory card from the CPU during a write process, this can make the content of the memory card invalid. The memory area retentivity might be lost as well. Under circumstances you might have to delete the memory card on the PG and reload the program. Observe the notes below before removing the memory card:

• Always remove the SIMATIC memory card only in STOP mode.
• Switch off the power supply.
• If there is no write access through the PG, you can also remove the memory card when the power is switched on in STOP mode. In this case it is better to disconnect all communication connections beforehand.

More information is available in the TIA Portal Online Help under

• "Accessing memory cards"
• "Add user-defined card reader"
• "Information about memory cards (S7-1200)"
• "Information about memory cards for S7-300 (S7-300/400)"

Additional Keywords
Memory cards

Description
If the setting in the PG/PC interface does not match the proper TCP/IP interface, communication between the Runtime simulation (simulation of the HMI panel) and the S7-1200 is not possible. All functions like "Download to CPU" and "Determine status online" work, but the Runtime simulation cannot set up a connection to the controller. Please also refer here to the relevant information in the STEP 7 Basic Online Help under "Simulating projects".

We recommend the following procedure as a remedy.

No.	Procedure:
1	Open the Control Panel via "Start > Control Panel" (in the Start menu for simplified access to the programs in Windows XP)   or via "Start > Settings > Control Panel" (for the classic Start menu as in earlier versions of Windows).
2	In the Control Panel you double-click on the "Set PG/PC Interface" icon. Fig. 01
3	Set the following parameters in the "Access Path" tab. Under "Access Point of the Application", select "S7ONLINE [STEP 7]" from the drop-down list. Under "Interface Parameter Assignment Used", mark the interface "TCP/IP(Auto) -> 3Com EtherLink XL", which is connected directly with the device. Then click on OK and also confirm the next message with OK. Fig. 02

More information on parameterizing the PG/PC interface and on the topics of

• Adding and installing more interfaces
• With or without automatic recognition of bus parameters
• Device driver cannot be selected or is not visible

is available in Entry ID: 11870489.

Note
The "TCP/IP(Auto)" setting in the PG/PC interface cannot be set in administrated networks if address assignment is by way of DHCP (Dynamic Host Configuration Protocol).

Instructions
You can send a STEP 7 V11 program by e-mail and download it locally without TIA Portal into the S7-1200 CPU if you have a SIMATIC memory card for the S7-1200 on both sides (sender and recipient). You can use a standard SD card reader to read and write a SIMATIC memory card.

With STEP 7 V11 you transfer the complete project to the SIMATIC memory card. Then you must copy the files with the Windows Explorer and send them by e-mail. On the receiver or partner side these files are again transferred to the SIMATIC memory card and downloaded into the S7-1200 CPU by slotting the card. The procedure is described in the table below.
 

No.	Procedure
1	Preparation Create your device configuration and your STEP 7 program in STEP 7 V11.
2	In the Properties of the CPU you change the startup mode from the default value "Warm restart - operating mode before POWER OFF" to "Warm restart – RUN". Open the "Device Configuration" and click "Startup" in the CPU Properties. Change the startup mode from "Warm restart - operating mode before POWER OFF" to "Warm restart – RUN". This setting is necessary for the CPU to start up automatically after transfer with the memory card. Fig. 01
3	Slot the memory card into your SD card reader and set the card type to "Transfer". For this, in the project navigation you right-click the relevant drive and open the "Properties" in the pop-up menu that opens. In the "Memory Card "<Drive:>"" dialog you select "Transfer" for the Card type and confirm with OK.
4	In the project navigation you click the CPU (PLC_1) and drag-and-drop the CPU to the memory card drive. The three directories "System data", "Program blocks" and Technology objects" are transferred when you copy the data to the memory card.
5	Now open the relevant drive with the Windows Explorer. The drive for the card must contain the files and directories below. The S7_JOB.S7S file A SIMATIC.S7S directory Fig. 02 Note These files must neither be changed nor deleted and are included in the as-delivered status of the SIMATIC memory card.
6	Create a ZIP file for the "S7_JOB.S7S" file and for the complete "SIMATIC.S7S" directory and send that ZIP file by e-mail to the desired recipient. If you use the WinZip tool, in some cases there might unwanted system properties and error messages. Microsoft provides the free tool 7-Zip as an alternative. Note As local recipient you can then unpack the files received and must store them in the same structure on your SIMATIC memory card. You can also use a completely new SIMATIC memory card for this. However, the memory card must have the same contents as described in Step 5 above.
7	As local recipient you then proceed as follows. With the system switched off you slot the memory card into the memory card slot of the S7-1200 CPU. Switch on the S7-1200 CPU. A flashing sequence between the "RUN/STOP", "ERROR" and "MAINT" LEDs indicates that the program is currently being transferred to the controller. The end of the transfer is indicated by the "RUN/STOP" LED lighting orange and the "MAINT" LED flashing at the same time. Switch off the S7-1200 CPU and remove the memory card from the slot. Then switch on the S7-1200 CPU again. The application then starts up automatically ("RUN/STOP" LED lights green). Note This process deletes all the data on the S7-1200 CPU and overwrites it with the contents of the memory card. The program on the memory card must always contain the complete S7-1200 application (device configuration and all the blocks). Even if you only want to update a modified block, nevertheless all the blocks must be on the memory card.

Creation environment
The pictures in this FAQ were created with STEP 7 V11.

Description
In STEP 7 V5.5 you can establish an online connection to an S7-300 or to an S7-400 and at the same time have an online connection between STEP 7 V11 and an S7-1200. In order to establish an online connection to the target systems you must assign the PG/PC interface an appropriate network access. The interfaces below are supported automatically:

• MPI
• PROFIBUS
• Industrial Ethernet (ISO and TCP/IP)

Open the PG/PC interface in the SIMATIC Manager of STEP 7 V5.5 with the menu command "Options > Set PG/PC interface..." and in the "Interface Parameter Assignment Used:" window you select the access point for your online connection as in Fig. 01.

Fig. 01

In STEP 7 V11 all the active network accesses of your PG/PC are in the "Online" accesses area in the project navigation. Via the menu command "Go online" you can have all the available interfaces displayed in a list. In the "Go online" dialog you select the type of the PG/PC interface to establish the online connection.

Fig. 02

More information is available in the Online Help of STEP 711 under:

• Connect PG/PC interface with a subnet
• Assign an IP address to a PROFINET IO device
• Go online with multiple devices
• Define PG/PC interface, go online
• Displaying accessible nodes

Description
When you upgrade your S7-1200 CPU with firmware V2, after downloading from STEP 7 (TIA Portal) the CPU does a warm restart the first time a change is made to RUN mode. A warm restart does not cause the data in the DBs and the monitoring values to be overwritten with the start values.

S7-1200 CPU modules that still have firmware version V1, are put into STOP mode when downloading from STEP 7 (TIA Portal) even if you are downloading just one block. When the change is then made to RUN mode, the cold start of the CPU deletes all the memory areas including the remanent memory areas and in the data blocks the monitored values are overwritten with the start values.

In this way, with the S7-1200 as from firmware V2 you have the option of downloading the changed data blocks to the CPU without the CPU going into STOP. Only if you put the CPU into STOP and then into RUN mode again will the monitoring values in the main memory be overwritten with the start values. Alternatively you can also overwrite the monitoring values by means of the monitoring table.

However, please note the two cases in which your CPU with firmware V2 nevertheless performs a cold start:

• When you download the project from STEP 7 V10.5 into a CPU with firmware V2.
• When you download your program in STEP 7 (TIA Portal) into a CPU with firmware V2, but you have a CPU with V1 configured in the device configuration.

The table below shows the differences between the S7-1200 and the S7-300/400 modules when you download data blocks from a CPU.
 

Action	S7-1200	S7-300/400
Storage of the start values with which a DB was downloaded into the CPU	In the load memory	In the load memory (values can no longer be read back from the load memory)
After download from the CPU	Start values are transferred back again from the load memory into the offline DB	The current monitored values are downloaded from the CPU and transferred to the "Start values" column in the offline DB.

Note
You can use the monitored values that the tags are currently capturing in the CPU as start values in the data block. Refer to the information in the STEP 7 (TIA Portal) Online Help under:

• "Use monitored values as start values"
• "Download blocks to device in RUN mode (S7-1200/1500)"
• "Download blocks to device in RUN mode (S7-300/400)"