ShopMill Program Template Auto-Generate Header and Footer NC Code

Overview

Every ShopMill part program typically starts with a tool-clearance move and ends with a spindle stop, coolant off, table re-home, and rewind-to-start sequence. Typing those lines by hand on every new workpiece is wasteful, error-prone, and inconsistent across operators. The standard fix is a program template: a pre-filled MPF file that contains the agreed header/footer NC code, the work-area clearance moves, and the operator message block. New part files are then created by copying that template rather than starting from an empty file.

How the template is implemented depends on the ShopMill front-end in use. Siemens currently ships three HMI variants for the 810D/840D platform:

• HMI Embedded – typical on 810D Powerline with PCU20 (the case in the source scenario).
• HMI Advanced – PCU50 / PCU70 on 840D Powerline.
• Sinumerik Operate (HMI sl) – PCU50.3 / NCU 7x0.3 and later on 840D sl.

All three can host a template, but the menu path and the file-naming rules differ. The procedure below covers each variant and also documents the related tool-change macro (L6.SPF) technique, which moves the same clearance logic into the tool change itself so that any part program benefits automatically.

Prerequisites

• ShopMill license active on the controller (option bit / CF card slot enabled).
• Operator password level that allows program editing and file management in the NC file system (default: manufacturer or service).
• Access to the active NC file directory (MPF, SPF, CMA, WKS) on the CF card or NCU file system.
• Knowledge of the active work offset, the fixed machine positions referenced by G75, and the spindle-clearance Z used on the machine.

Reference: The G-Code and M-Code Lines Involved

The header/footer block cited in the field report is built from the following Siemens (DIN 66025) codes. Reference them when building or auditing the template.

Method 1 – Template Workpiece (HMI Embedded / Operate)

Siemens documents a template workpiece feature for the standard HMI: a user-defined NC file that the system uses as the starting content for any newly created program. The official reference is the HMI Embedded / Operate programming manual, entry Siemens Support Entry 55622848 (chapter 6.7.12 in the embedded manual). Behavior is identical between ShopMill and ShopTurn under that entry.

Step-by-Step (HMI Embedded, PCU20)

1. On the ShopMill start screen, navigate Program Manager > Templates. If the directory does not exist, create it under /_N_TEMPLATES_DIR from the services area.
2. Create a new program file named, for example, _TPL_MPF in the templates directory. Use the underscore-leading naming convention reserved for system templates so the HMI does not display it in the main program list.
3. Edit the file and paste the header/footer skeleton. Mark the editable region with a ShopMill program-section comment so the operator can locate the part-specific blocks:

   ;SHOPMILL TEMPLATE v1.0 - DO NOT EDIT HEADER/FOOTER
   G75 Z0.
   G75 X0. Y0.
   ;*** PROGRAM CONTENTS BELOW ***
   
   
   ;*** END PROGRAM CONTENTS ***
   M5
   M9
   G75 Z0.
   G75 Y0.
   G500 G00 X320.
   MSG(" *** END PROGRAM *** ")
   M30

4. Save, then exit edit mode.
5. From the user area, choose New > Part Program. The HMI will pre-fill the new file with the template body if the controller is configured to do so (see verification step below).

Method 2 – Manual Copy of a Master Program

If the HMI variant does not support template workpieces, or the controller has been locked down to operator level only, the standard shop-floor workaround is to keep a master program in the work directory and copy it for every new part. This works on every ShopMill version, including legacy HMI Embedded PCU20 on 810D Powerline.

1. Create the master file once: MASTER.MPF containing the header/footer shown above.
2. Mark the file as read-only using the file-system attributes from the services area (SEDIT > file attributes) so operators cannot accidentally edit the master.
3. Train operators to right-click the master, select Copy, and rename the copy to the part number. The ShopMill editor opens the new file with all of the standard lines already in place.
4. Optionally, set the Program Manager default directory so that MASTER.MPF is always visible in the root of the work area.

This method has the advantage of working on any firmware version and is the fallback when Method 1 is not available. The disadvantage is that operators must remember to copy from the master; a single distracted keystroke creates a blank file and the safety envelope is lost.

Method 3 – Move the Logic into the Tool-Change Macro (L6.SPF)

The field report's author solved the same problem differently: by modifying the tool-change program L6.SPF so that the clearance moves happen before every T-call. This puts the safety envelope in one place that every program (new, legacy, or imported) inherits automatically, and it removes the dependency on operator discipline.

Recommended L6.SPF Skeleton

;L6.SPF - TOOL CHANGE MACRO (rev. 2)
;Moves spindle to clearance Z, sends table to machine zero,
;performs tool change, then resumes the calling program.

G75 Z0.                 ; lift spindle to fixed clearance point
G75 X0. Y0.             ; table to machine zero (clears workpiece)
M1                      ; optional stop - active only with OP stop
T=__                    ; tool change call (parameter from caller)
M1                      ; second optional stop for prove-out
RET

Behavior Notes

• The first M1 pauses after the clearance moves; the second pauses after the tool is in the spindle. With the HMI's Program control / Single block or OP stop on, the operator gets two deliberate confirmations - useful when proving long-cycle programs or when coolant hoses need to be repositioned between tools.
• Add a T0 pre-call at the very start of the part program to clear the spindle before the first useful cut, and a T0 at the end of the part program so the macro runs one final time after the last tool finishes. This delivers the same header/footer behavior without the operator typing it.
• Because L6.SPF executes from the NC kernel, it does not need the part program to be a template. Even hand-edited MPFs or programs imported from CAM inherit the safety envelope.

HMI Variant Comparison

Verification

After installing a template - by any of the three methods - run the following checks before releasing the change to production:

1. New-program test. Create a brand new MPF from the user area. Confirm the header lines (G75 Z0 / G75 X0 Y0) are present and the footer (M5, M9, G500 G00 X320., MSG, M30) is present, in that order.
2. Block search. Use the HMI's Block search with calculation to start the program at the last block before M30. Confirm the controller computes a valid approach to the MSG(" *** END PROGRAM *** ") block and stops cleanly. A calculation error here usually means the work offset is still active and G500 is missing from the footer.
3. Tool-change prove-out. With Dry run and OP stop enabled, run a two-tool program. Confirm the spindle lifts to clearance Z and the table moves to machine zero before each tool change. This verifies the L6.SPF modifications if Method 3 is used.
4. MSG line test. Cycle the program; verify the HMI message bar shows *** END PROGRAM *** at the end and the channel rewind indicator returns to block 1.
5. Backup. Archive the template file (_TPL_MPF or MASTER.MPF) and the modified L6.SPF to a versioned backup before sign-off. Both files live in CF card paths that are erased on a series start-up if not backed up.

Troubleshooting Matrix

Best-Practice Notes

• Single source of truth. Choose one of the three methods per machine. Mixing a template file with an L6.SPF rewrite creates two places to maintain and the two can drift when a ShopMill update changes the tool-change cycle.
• Document the footer. Print the footer sequence on a laminated card next to the operator panel. M5 / M9 / G500 / G00 / MSG / M30 is the conventional order; deviating from it confuses service engineers who later audit the NC code.
• Guard the work offset. Always re-issue G500 (or the canonical G54+) at the start and end of a program. A forgotten G500 after a subprogram that left G54 active is the single most common cause of first-cut crashes on a re-run part.
• Use MSG, not comment lines, for operator messages. A leading-semicolon comment is invisible in the HMI status line; the MSG(" … ") command is shown until cleared with MSG("") or until a new MSG is issued.
• Back up the template before every ShopMill upgrade. The upgrade procedure in Siemens Support 55622848 may reset the template directory if the install is performed at manufacturer level.

FAQ