Control File (C-File)

The optional control file is used to get information about a currently running analysis.

While a simulation is running, it can be very useful to find out more information than is printed in the Engine output file. This can be done using a Radioss control file which has the same prefix name as the current Engine input file but ends in *.ctl. If the current running Engine file is named TensileTest_0001.rad, then the control file should be named TensileTest_0001.ctl.

Some reasons to use a control file include:
  • Retrieve the current state of the simulation including current simulation time, time step, cycle, energy information, and estimated remaining time
  • Stop the computation immediately, or at a specified time or cycle number
  • Create an animation immediately, or at a specified time or cycle number
If a simulation is launched in the Altair Compute Console with solver control options checked, the following dialog will appear and a control file will be created automatically using the selected options when the Send Command button is selected.


Figure 1.

If the Compute Console (ACC) is not being used, the control file can be created using a text editor and saved in the directory where Radioss is writing the Engine output file.

The following options are available to be used in the control file with each option placed on its own line. Unless /TIME or /CYCLE is included, the action is taken immediately after Radioss reads the control file. Otherwise, the action is taken at the /TIME or /CYCLE specified.
Action
Result
/ANIM
Create an extra animation file (A###). The output frequency defined in the Engine file will not change when this option is used.
/CHKPT
Create a file named CHECK_DATA which contains /RERUN commands to continue a simulation if it is stopped. Usually used in combination with /STOP to stop the simulation. Not available with the implicit solution.
/CYCLE/cycleNumber
The control file commands will be executed at the specified cycle number.
/H3D
Write animation data to the *.h3d file. The output frequency defined in the Engine file will not change when this option is used.
/INFO
Returns information on current cycle, current global energies, current time step. This information is always written for all options.
/KILL
Kill the simulation and do not create a restart file.
/RFILE
Create a restart file.
/STOP
Stop the simulation and create a restart file, so it can be restarted.
/TIME/timeValue
The other control file commands will be executed at the specified simulation time.

When Radioss detects the control file, the current status of the simulation is written in the same control file using the options were entered.

For example, a simulation is running on remote system and thus not started using the Altair Compute Console. Since the Engine input file is named, TensileTest_0001.rad, a control file named TensileTest_0001.ctl is created with the following information and uploaded to the working directory of the simulation.
/TIME/.1
/ANIM
/CHKPT
/STOP
When Radioss detects the control file, the following information is written into the same TensileTest_0001.ctl file with information about the current state of the simulation and execution of the control file commands. At t=0.1 in the simulation, Radioss will create an animation file, a CHECK_DATA file, a restart file, and stop the simulation.
RUN CONTROL FILE
 ----------------

 WRITE NEXT ANIMATION FILES AT TIME  0.1000000                                                                                 
 WRITE NEXT RESTART FILE AT TIME  0.1000000                                                                                 
 RUN STOP AT TIME  0.1000000                                                                                 

 CURRENT STATE:
 --------------
 CYCLE      =     13040
 TIME       = 0.8153611E-02
 TIME STEP  = 0.6252749E-06SOLID      70
 ENERGY ERROR      =  0.0%
 INTERNAL ENERGY   = 0.1188329E-02
 KINETIC ENERGY    = 0.1050914E-07
 ROT. KIN. ENERGY  =  0.000000    
 EXTERNAL WORK     = 0.1188431E-02
 MASS.ERR (M-M0)/M0=  0.000000    
 
 CURRENT ELAPSED TIME    =          4.88 s 
 REMAINING TIME ESTIMATE =        594.04 s