How to Connect and Download Program to S7-400

An Overview of S7-400

The S7-400 is the most powerful PLC in the SIMATIC controller family. This allows efficient automation technologies with Totally Optimized Automation (TIA). The S7-400 is an automation platform for device solutions in manufacturing and process engineering, distinguished primarily by its modularity and architecture.

How to connect to PC?

Step 1) Open Simatic Manager Software


Step 2) Click on the accessible node icon to check whether the communication is Ok or Not.


Step 3) If communications are good, you will see a window pop up similar to the one below. If so, close the Accessible Nodes window and continue to the download or upload portion.


Note: you will get a popup message like below if your communication fails

Step 4) Set PG/PC interface


You need to match the “PG/PC” interface to start communication to the PLC. For this, select the menu Options-> Set PG/PC Interface.

Step 5) The following dialog box will appear, showing all the various interfaces (i.e., communication drivers).


Note: Every cable has its own interface. Select the TCP/IP protocol for your network card on Ethernet. Be careful not to choose an Ethernet wireless link.

Step 6) It is best to choose an interface with automatic status to make it work faster. This would discover and use working configurations automatically.

How to Download Program?

Step 1) First, to enable the download menu commands, you must select the block folder at the project station where you want to download.


You can download the program through three methods. They are

a) Partial download of selected blocks

b) Full download of all blocks and system data

c) Complete deletion of online PLC blocks and then downloading of all blocks and system data

Partial Download

Step 1) Partial transfers are found in current projects where only one or two blocks are copied. To execute this sort of update, pick the block(s) you want to download and then select the PLC > Download menu item or the Download button.


Step 2) Holding down either the Shift key or Ctrl Key allows more than one block to be selected at a time. Note that the download order will occur in the order in which the blocks are selected. This means that an error will occur if you call a block before downloading the block.

Step 3) The CPU should be in Stop mode before downloading the System Data Block (SDB) Because this is the equivalent of a hardware configuration download. Normally, this is not necessary for a PLC because it has already had its hardware configured. If you download the device files, the following notifications will prompt you through the transitions.



Step 4) If the CPU is in run mode, you will be prompted to stop the CPU. When you click OK, the software will run and stop transitioning


Step 5) After you download the SDB, you will be asked to run the CPU again.


Step 6) Click Yes will automatically bring the CPU back to run mode.

Full download of all blocks and system data

To import all blocks at once, make sure that you are in the Block folder and select Edit > Select All menu object. Tap the Download button. You will be prompted to overwrite any existing blocks and if you want to load the system data (see above) (see above)

Clearing the CPU Memory and then Downloading

Partial and full download approaches will erase existing blocks but will not overwrite any blocks from memory. To remove the current software in the CPU and download a new project, pick the Blocks folder, and then use the menu item PLC > Download User Program to Memory Card.


The following dialog box prompts you to delete all blocks and project data in the PLC. Click Yes to take action.


Follow the normal download procedure after this.