Running in non-GUI Mode

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The simulator can be run in a non-interactive non-GUI mode independently of the front end. This is useful for running simulation 'batches' controlled by a proprietary script or language or DOS batch files.

Under Windows, the simulator will run as a 'console mode' application and no GUI elements will be created.

When run in this mode, the simulator will read in the specified netlist, run the simulation then close and return control to the calling program. It will generate a binary data file and a list file.

Important Licensing Information

Non-GUI mode is only possible if you are using network licensing. This feature is not available if you are using a portable (i.e. dongled) license. Please contact support if you have a non-network license and wish to use non-GUI simulation mode.

This mode of operation is 'counted' for licensing purposes. This means you can only run one non-GUI simulation process for each license issued even if all are run by a single user on a single machine. By contrast, regular simulation initiated manually through the GUI are not counted and any number of runs may be initiated on the same machine by the same user for this purpose.

These restrictions have been made to limit exploitation of multiple core machines for simulations run from non-SIMetrix environments.


The command syntax is as follows:

SIM [/config "config_location"] [/gui mode] [/check] [/an "analysis_line"]
[/list list_filename] [/options "options"] [/nolist] [/lowPriority]
[/nodata] [/k] [/extraline extra_line] netlist_file [data_file]
config_location Location of file holding configuration settings. Configuration settings include global options and global model library locations. The value must be of the form:


pathname may use system symbolic path values such as %EXEPATH%. See User's Manual/Sundry Topics/Symbolic Path Names for details.

If not specified, the configuration settings will be taken from the Base.sxprj file. See the User's Manual/Sundry Topics/Configuration Settings/Default Configuration Location for details on where this file is located.

Alternatively, you can specify the location using a setting in the startup.ini file. Add a value called SimConfig to the [Startup] section and give it a value of:


The startup.ini file must be located in the same directory as the SIMetrix executable binary. (SIMetrix.exe on Windows). See User's Manual/Sundry Topics/SIMetrix Command Line Parameters/Using startup.ini for more information on the startup.ini file.

Note that the /config switch if present must always appear before the first argument to the command.
mode Mode of operation. Default = -1. Valid values are -1, 0, 1 and 2 but only -1 and 1 are meaningful for stand-alone operation. 0 and 2 are used when starting the simulator process from the front end. -1 (same as omitting /gui) runs the simulator in console mode with all messages output to the console or terminal window. 1 enables GUI mode where the simulator runs in a stand-alone mode but displays a graphical status box showing messages and simulator progress. This mode is used by the 'asynchronous' menus in the front end.
analysis_line If /an switch is specified, analysis_line specifies the analysis to be performed and overrides all analysis lines specified in the netlist.
list_filename Name of list file. Default is main netlist file name with extension .OUT. Enclose path name in quotes if it contains spaces.
options List of options valid for .OPTIONS statement.
netlist_file File name of netlist.
data_file File to receive binary data output.
/check If specified, the netlist will be read in and parsed but no simulation will be run. Used to check syntax
/nolist If specified, no list file will be created
/lowPriority If specified, the simulator will be run as a low priority process, i.e. in the background. Recommended for long runs.
/nodata Only vectors explicitly specified using .KEEP or .PRINT will be output to the binary file. Equivalent to '.KEEP /nov /noi /nodig' in the netlist.
/k If specified, the program will not finally terminate until the user has pressed enter and a message to that effect will be displayed. Under Windows, if the program is not called from the DOS prompt but from another program, a console will be created for receiving messages. The console will close when the program exits sometimes before the user has had a chance to read the messages. This switch delays the exit of the program and hence the destruction of the console.
extra_line An additional line that will be appended to the netlist. This permits simple customisation of the netlist. This should be enclosed in double quotation marks if the line has spaces.


Press cntrl-C - you will be asked to confirm. The simulation will be paused while waiting for your response and will continue if you enter 'No'. This is an effective means of pausing the run if you need CPU cycles for another task, or you wish to copy the data file. See Reading Data.

Reading Data

A data file will be created for the simulation results as normal (see The Binary Data File). You can read this file after the simulation is complete use the SIMetrix menu File > Data > Load... . You may also read this data file while the simulation is running but you must pause the simulation first using cntrl-C.

Important: if you read the data file before the simulation is complete or aborted, the file entries that provide the size of each vector will not have been filled. This means that the waveform viewer will have to scan the whole file in order to establish the size of the vectors. This could take a considerable time if the data file is large.