Basics

Application

You can use the Q, QL, QR and QS parameters of the control, also referred to as variables, to take measurement results into account dynamically within calculations while machining.

  • For instance, you can program the following syntax elements variably:
  • Coordinate values
  • Feed rates
  • Spindle speeds
  • Cycle data

This means that the same NC program can be used for different workpieces and values have to be changed in only one central place.

Description of function

8H000169

Variables always consist of letters and numbers. The letters determine the type of variable and the numbers its range.

For each variable type, you can define the variable range that the control displays on the QPARA tab of the Status workspace.

Defining the contents of the QPARA tab

Variable types

Q parameters

Q parameters affect all NC programs in the control’s memory.

Q parameters have a local effect within macros and machine manufacturer cycles. This means that the control will not return changes to the NC program.

The control provides the following Q parameters:

Variable range

Meaning

0 to 99

User-defined Q parameters, if there are no overlaps with the HEIDENHAIN SL cycles

100 to 199

Q parameters for special functions on the control that can be read by user-defined NC programs or by cycles

200 to 1199

Q parameters for functions defined by HEIDENHAIN (e.g., cycles)

1200 to 1399

Q parameters for functions defined by the machine manufacturer (e.g., cycles)

1400 to 1999

User-defined Q parameters

QL parameters

QL parameters are active locally within an NC program.

The control provides the following QL parameters:

Variable range

Meaning

0 to 499

User-defined QL parameters

QR parameters

QR parameter affect all NC programs in the control’s memory; they are retained even after a restart of the control.

The control provides the following QR parameters:

Variable range

Meaning

0 to 99

User-defined QR parameters

100 to 199

QR parameters for functions defined by HEIDENHAIN (e.g., cycles)

200 to 499

QR parameters for functions defined by the machine manufacturer (e.g., cycles)

QS parameters

QS parameters affect all NC programs in the control’s memory.

QS parameters have a local effect within macros and the machine manufacturer cycles. This means that the control will not return changes to the NC program.

The control provides the following QS parameters:

Variable range

Meaning

0 to 99

User-defined QS parameters, if there are no overlaps with the HEIDENHAIN SL cycles

100 to 199

QS parameters for special functions on the control that can be read by user-defined NC programs or by cycles

200 to 1199

QS parameters for functions defined by HEIDENHAIN (e.g., cycles)

1200 to 1399

QS parameters for functions defined by the machine manufacturer (e.g., cycles)

1400 to 1999

User-defined QS parameters

Q parameter list window

In the Q parameter list window, you can view and edit the values of all variables.

AS_6_24_Q-Parameterliste
Q parameter list window, showing the Q parameter values

In the left-hand panel, you can select the variable type to be displayed.

  • The control displays the following information:
  • Variable type (e.g., Q parameter)
  • Number of the variable
  • Value of variable
  • Description in case of pre-assigned variables

If the cell in the Value column is displayed with a white background, you can edit its value.

 
Tip

While the control is executing an NC program, you cannot edit the variables using the Q parameter list window. Changes are only possible while a program run has been interrupted or aborted.

Status overview on the TNC bar

This status is reached after an NC block has been executed, for example in the Single Block mode

  • The following Q and QS parameters cannot be edited in the Q parameter list window:
  • Variable range from 100 to 199, because there might be interferences with special functions in the control.
  • Variable range from 1200 to 1399, because there might be interferences with machine manufacturer-specific functions.

Variable types

  • The following search options are available in the Q parameter list window:
  • Search the entire table for any strings
  • Search the NR column for a unique variable number

Searching the Q parameter list window

  • You can open the Q parameter list window in the following operating modes:
  • Editor
  • Manual
  • Program Run

In the Manual and Program Run operating modes, the window can be opened with the Q key.

Searching the Q parameter list window

  1. To search the Q parameter list window:
  2. Select any cell with a gray background
  3. Enter the desired string
  4. The control opens an input field and searches the column of the selected cell for this string.
  5. The control marks the first result that starts with the search string.
QsDropDown

  1. Select the next result, if necessary
 
Tip

The control displays an input field above the table. Alternatively, you can use this input field to navigate to a unique variable number. To select the input field, press the GOTO key.

Notes

 
Notice
Danger of collision!
HEIDENHAIN cycles, machine manufacturer cycles and third-party functions use variables. You can also program variables within NC programs. Using variables outside the recommended ranges can lead to intersections and thus, undesired behavior. Danger of collision during machining!
  1. Only use variable ranges recommended by HEIDENHAIN
  2. Do not use pre-assigned variables
  3. Comply with the documentation from HEIDENHAIN, the machine manufacturer and third-party providers
  4. Check the machining sequence using the simulation

Preassigned Q parameters

  • You can enter fixed and variable values mixed in the NC program.
  • You can assign a maximum of 255 characters to QS parameters.
  • You can use the Q key to create an NC block to assign a value to a variable. If you press the key again, the control changes the variable type in the order Q, QL, QR.
  • On the virtual keyboard, this procedure only works with the Q key in the NC functions area.

    Virtual keyboard of the control bar

  • Variables can be assigned numerical values between –999 999 999 and +999 999 999. The input range is limited to 16 digits, of which 9 may be before the decimal point. The control can calculate numerical values up to 1010.
  • You can reset variables to the Undefined status. For example, if you program a position using an undefined Q parameter, the control ignores this movement.
  • Assigning the Undefined status to a variable

  • The control saves numerical values internally in a binary number format (standard IEEE 754). Due to the standardized format used, some decimal numbers cannot be represented with a binary value that is 100% exact (rounding error).
  • If you use calculated variable values for jump commands or positioning moves, you must keep this in mind.

Notes on QR parameters and backup

The control saves QR parameters within a backup.

If the machine manufacturer did not define a specific path, the control saves the QR parameters in the following path: SYS:\runtime\sys.cfg. The SYS: partition will only be backed up in full backups.

  • Machine manufacturers can use the following optional machine parameters to specify the paths:
  • pathNcQR (no. 131201)
  • pathSimQR (no. 131202)

If the machine manufacturer used the optional machine parameters to specify a path on the TNC: partition, you can perform a backup with the NC/PLC Backup functions without entering a code number.

Backup and restore