SIMIT Unit (also known as Simulation Unit)

SIMIT Unit

The SIMIT Unit is a Hardware component developed by Siemens to simulate PROFINET or PROFIBUS bus participants. It is used to simulate decentralized peripheries PROFINET/PROFIBUS IO systems (e.g. ET200s) in a Hardware-in-the-loop environment, meaning programming a real PLC against a machine simulated using Simcenter Amesim. All variables that are part of a simulated component (e.g. ET200 IO-addresses or SINAMICS control- & status-words) can be read or written using an API.

When connecting the Automation Connect tool to a SIMIT Unit, you need an existing Simulation Unit project (*.spf). A Simulation Unit project can be created using the associated Simulation Unit software, where you can import hardware- and symbol-configuration from your PLC engineering program (like TIA Portal, STEP7 Classic or SIMOTION SCOUT) to simulate projected bus-networks.

A short instruction will be given below; for a detailed explanation please refer to the SIMIT Unit help documentation.

Exporting hardware- and symbol-configuration in TIA Portal

TIA V13 doesn't offer a direct way to export a hardware setup, so for extracting the configuration a temporary compiler file is used. To prevent TIA Portal from deleting this file after translating, you need to unlock this function by executing the provided UnlockHWConfig.exe once. This tool can be found in the installation directory of the Simulation Unit program in the subfolder TIAImport. Afterwards you need to recompile / translate your project once more, which can be done by right-clicking your projected PLC, select Compile and Hardware (rebuild all), which creates a EsToAs_HWConfiguration.oms file in C:\Users\Public Documents\TIAExport \HwConfiguration\DOWN[Project name]\r00s001\ (see figure below).

STEP7 Classic or SIMOTION SCOUT projects on the other hand create an sdb3000.dat file in [STEP7 installation directory]\s7Tmp\SDBDATA\s7hwcnfx\DOWN\r00s02. Depending on the installed program-version, the installation path can slightly change; in this case, please refer to the Simulation Unit help documentation.

Figure 15: Exporting hardware-configuration from a TIA-Portal project

In addition to the hardware-configuration, you also need the symbol table. Otherwise you'll only get the projected addresses without higher-level information like symbol-names, comments or symbol-type. This information can be exported in a MS Excel-file inside the TIA Portal in your PLC Variable overview:

Figure 16: Exporting symbol-configuration from a TIA Portal project

Creating a Simulation Unit project

Creating a Simulation Unit project

To download and simulate your Hardware-configuration in the SIMIT Unit, you first need to create a Simulation Unit project using the associated software, which can be downloaded from the Siemens Industry Online Support. After starting the program, you need to create a new project (see following figure). Note that the previous versions of the SIMIT Unit are called Simulation Unit or SIMBA, and all these names might still be used in the program.

Figure 17: Creating a new Simulation Unit project

Afterwards you need to import your hardware configuration. For this step select Menu

Configuration > Import hardware. In the appearing dialog you need to select the Simulation Unit you want to use and add the earlier exported *.oms file (from TIA Portal). Afterwards you can select which devices you want to import (see following figure).

If the simulation unit isn't listed, make sure you are connected to the Control-Port (CTRL) of the Simulation Unit via Ethernet and you are operating in the same subnet. If that's the case you should be able to scan the network for your Simulation Unit.

Figure 18: Importing a hardware configuration

Importing a hardware configuration

After importing the hardware-configuration using the *.oms file, you can check the projected hardware-setup by opening the hardware view (see following figure). If you want to manually add, remove or modify your setup you can do so by selecting Menu

Configuration > Configure hardware. For further information please refer to the Simulation Unit help documentation.

Figure 19: Projected hardware-setup in the Simulation Unit

Connecting to the Automation Connect tool

For loading an existing Simulation Unit project open the Automation Connect tool, switch to the Simulation Unit tab, click the Load button and select the *.spf-folder:

Figure 20: Simulation Unit connector tab

Simulation Unit connector tab

If the Simulation Unit project contains no (or an invalid) IP for connecting to the Simulation Unit, an input window for entering a new IP will appear (see previous figure).

If the Simulation Unit project is missing symbol names, you can import a table containing the plc-tags using the button Import Symbol-Config. This will automatically merge or split existing addresses to match the defined variable-sizes. Allowed are Excel-tables (exported from TIA-Portal), SEQ-files (exported from STEP 7 or PCS 7) or gateway.config files created by SIMIT:

Figure 21: Importing a symbol-config for Simulation Unit

Importing a symbol-config for Simulation Unit

Because not all data can be stored inside the native Simulation Unit project, after importing a symbol-config, a separate csv-file is created inside the Simulation Unit project directory named VariableTemplates.csv. This file contains all imported data (symbol names, datatypes, addresses and comments) and will be loaded first next time this Simulation Unit project is loaded.