### 17.3.3. I/O Control Parameters

General I/O Control
`include pref in forces`
Type | Logical
Default Value | f
Description | If set to `'t'`, the solver will account for the specified reference pressure in the force and moment calculation.
`mcf concentrations output option`
Type | Integer
Default Value | 2

Description

Controls the output of mass concentrations, molar concentrations and molar fractions to the results file.

0 = Determine what data to write from the VARIABLES file (or CCL)

1 = Do not write this data

2 = Do not write this data for mixture fraction based models, and do write this data for other combustion models or no combustion model

3 = Always write this data

To achieve full backwards compatibility with version 10.0, set this parameter to 3. Note that, in the case of a large number of components (>20), the computational cost of writing the data may be unacceptably high.

`read boundary flows`
Type | Logical
Default Value | f
Description | When set to `'t'`, the solver reads in boundary flows from the initial values when restarting from a previous run. This helps with smooth restart of cases with user function CEL expressions involving forces or boundary flows.
Backup Results
`backup file at start`
Type | Logical
Default Value | f
Description | Controls whether a backup file is written at the start of every run (that is, showing the initial values field for the run). Mass flow information written to a backup file at the start of the run is not accurate. To calculate accurate mass flow from a backup file, use information from the backup file written after the first timestep/iteration of the run.
`backup file at zero`
Type | Logical
Default Value | f
Description | Controls whether a backup file is written after zero timesteps (that is, showing the initial guess field for the run). Mass flow information written to a backup file at time zero is not accurate. To calculate accurate mass flow from a backup file, use information from the backup file written after the first timestep/iteration of the run.
Transient Results
`mfloip to trn files`
Type | Logical
Default Value | f
Description | When set to `'t'`, integration point mass flows are written to transient files (`*.trn`). This will ensure numerically consistent mass flow evaluations when postprocessing transient files.
Output File and Monitor Data
`always output postprocessing`
Type | Logical
Default Value | f
Description | When set to `'t'`, makes the solver output flow summaries, variable ranges, forces, moments and scales to the output file on intermediate adaption steps
`monitor digits`
Type | Integer
Default Value | 8
Description | Controls the number of digits used in the MON file. Increase the value to increase the precision of the results reported.
`monitor ftrans`
Type | Logical
Default Value | f
Description | When set to `'t'`, outputs false transient information (steady-state only) to the Solver output file (`*.out`) file for each coefficient loop.
`monitor ranges`
Type | Logical
Default Value | f
Description | When set to `'t'`, outputs variable ranges for each coefficient loop in a steady-state simulation or for each timestep in a transient simulation.
`monitor scales`
Type | Logical
Default Value | f
Description | When set to `'t'`, outputs variable scales for each coefficient loop in a steady-state simulation or for each timestep in a transient simulation.
`wall clock time`
Type | Logical
Default Value | f
Description | Output wall clock time at the start of each outer loop in a steady-state run or timestep loop in a transient run and in the summary at the end of the run.

Release 18.2 - © ANSYS, Inc. All rights reserved.