Configuring SINUMERIK 840D sl OP Hardkeys via systemconfiguration.ini

The SINUMERIK 840D sl operator panel (OP) exposes a column of horizontal and vertical keys on the left of the display that are frequently referred to as "hardkeys" because they are physical membrane switches rather than touchscreen buttons. Configuring which PLC signal, NC function, or HMI dialog each key invokes is performed through the systemconfiguration.ini file on the TCU (Thin Client Unit) or PCU (PC Unit). This reference documents the hardware identification, the section/syntax of the INI file, the PLC interface for MLFB 6FC5203-0AF05-1AB0, and the commissioning sequence required to make custom key assignments live on the HMI.

1. Hardware Identification: MLFB 6FC5203-0AF05-1AB0

The operator panel referenced in the source query carries the Siemens MLFB (machine-readable product designation) 6FC5203-0AF05-1AB0. The 6FC5203 series designates the OP 010 / OP 010C 10.4-inch TFT operator panel used with the SINUMERIK 840D sl line. The -0AF05-1AB0 suffix defines the variant:

OP 010 is paired with a TCU (e.g., 6FC5312-0DA00-0AA0) or a PCU 50.5 and connected over Industrial Ethernet to the NCU (Numerical Control Unit). The membrane keys on the left side of the panel are wired to a dedicated key controller inside the OP; the controller reports key state to the HMI software through a standardized HMI/PLC interface.

2. Hardkey vs. Softkey Architecture on 840D sl

840D sl operator panels expose three classes of keys, and conflating them is the most common cause of failed configuration attempts:

• Softkeys (horizontal): Eight function keys rendered along the bottom of the active HMI dialog (F1–F8 in the active mask). Their labels are dynamic and are driven by the dialog selected in the HMI. Configured per dialog, not globally.
• Softkeys (vertical): The column of keys rendered on the right edge of the display. Same dynamic-label mechanism as horizontal softkeys, also dialog-scoped.
• Hardkeys (membrane): Physical keys on the left side of the OP and along the top strip. These have fixed positions and fixed mechanical labeling (e.g., MEAS, JOG, MDA, AUTO, channel advance, feed/spindle override). They are addressed by a fixed hardware index, not by a dialog context.

The keys the source query targets are the left-side hardkeys (membrane switches). These are not freely user-definable in the same way softkeys are; the HMI hardkey layer ships with a Siemens-defined default assignment. The assignment can be extended or overridden in systemconfiguration.ini for OEM-specific functions, but the base Siemens key set cannot be removed.

3. systemconfiguration.ini Location and Structure

The systemconfiguration.ini file is stored on the boot volume of the TCU/PCU:

C:\Program Files (x86)\Siemens\MotionControl\oem\sinumerik\hmi\cfg\systemconfiguration.ini

On older PCU 50.3 systems, the path may be:

D:\User\OEM\sinumerik\hmi\cfg\systemconfiguration.ini

The file is plain ASCII, INI-formatted, with semicolon (;) as the comment character. Its top-level sections relevant to hardkey configuration are:

4. Hardkey Address Map

Each membrane key on the OP 010 has a fixed hardware address. The address is reported by the HMI runtime to the PLC on every key event (press and release) through the HMI/PLC interface. The default address map for the left-side column on OP 010 is:

The 16-bit input word from the HMI to the PLC is DB19.DBB0 (also readable as DB19.DBX0.0 through DB19.DBX0.7 and the second byte DB19.DBB1 for keys 9–16). The acknowledgement word from the PLC back to the HMI is DB19.DBB2.

5. systemconfiguration.ini Hardkey Section Syntax

To remap a key, add or modify the [HARDKEYS] section. Each line uses the form:

KeyID = Action

Where KeyID is the index from the address map and Action is one of:

• A Siemens internal action token (e.g., JOG_MODE, AUTO_MODE, MEAS_TRIGGER)
• A PLC address trigger in the form PLC:DB<n>.DBX<byte>.<bit>
• An HMI dialog launch: HMI:dialog_name
• A custom OEM action defined in oem.ini

Example [HARDKEYS] section binding the second hardkey to a custom PLC bit on DB100:

[HARDKEYS]
; Remap hardkey 2 to set OEM bit DB100.DBX10.0 on press
Key2 = PLC:DB100.DBX10.0
; Hardkey 5 launches custom measuring dialog
Key5 = HMI:smeas_custom
; Hardkey 7 reserved for spindle override (default)
Key7 = SPINDLE_OVERRIDE
; Hardkey 8 reserved for feed override (default)
Key8 = FEED_OVERRIDE

For pulse (edge-triggered) versus level-triggered behavior, the syntax supports an optional modifier:

Key2 = PLC:DB100.DBX10.0:EDGE
Key3 = PLC:DB100.DBX10.1:LEVEL

Default behavior is EDGE (single press sets the bit until the HMI acknowledges the press), matching Siemens convention.

6. PLC Interface Programming

The PLC side of the interface is an FB (function block) in the machine project. The default block for the HMI hardkey interface on 840D sl is FB2 (HMI Interface) within the Siemens base PLC program. The signal direction is:

To respond to a hardkey press in the PLC, monitor the appropriate bit in DB19.DBB0 and latch a state bit in the user program. Minimal STL snippet:

// FB1 - Hardkey Handler (called each PLC cycle)
A DB19.DBX0.0 ; // Hardkey 1 (MEAS) pressed
S M100.0 ; // Latch OEM meas trigger
AN DB19.DBX0.0 ; // Released
R M100.0 ; // Unlatch if level-triggered

// LED control: turn on key 1 LED while in JOG
A "Mode_JOG_active" ; // user mode bit
= DB19.DBX2.0 ; // Hardkey 1 LED on

For an S7-1500-based 840D sl PROFINET variant, the same addresses are accessible from the user program via the data block "HMI_Interface" created by the project wizard.

7. Language and Regional Parameters

The source query also asks about "the meaning of the language" in the hardkey configuration context. Within systemconfiguration.ini, the relevant language parameter is in the [HMI] section:

[HMI]
Language = en_US ; or de_DE, zh_CN, etc.
; Language affects hardkey label rendering if labels are
; taken from text resources (HMI.txl) rather than hardcoded

The default label set for hardkeys is stored in HMI.txl in the language directory of the HMI runtime. To add a second language for the OEM key label layer, supply a parallel HMI.txl in the OEM folder. The HMI runtime falls back to the OEM copy if the active language has no entry for the custom keys.

8. Commissioning Procedure

Follow this sequence to bring a custom hardkey configuration live on the OP 010:

1. Backup. Copy the existing systemconfiguration.ini to a dated backup directory on the same volume or to a USB stick.
2. Edit offline. Use a plain-text editor (Notepad++ is the de-facto choice, with INI syntax highlighting) to modify the file. Do not use Word or any rich-text editor; it will corrupt the line endings.
3. Validate syntax. Open the file in the HMI's built-in INI checker (Service menu → Diagnostics → INI Files) or run slsnhmicfg -v from a TCU shell if SSH/service access is enabled.
4. Stop the HMI. From the Service menu, select Stop HMI, or use the equivalent command line slsnhmictrl stop. Wait for the "HMI stopped" confirmation.
5. Replace the file. Overwrite systemconfiguration.ini with the edited version.
6. Start the HMI. From the Service menu, select Start HMI. Allow 60–90 seconds for the runtime to come back up.
7. Verify. Press each remapped key and confirm the expected PLC bit is set in the online monitor. Check DB19.DBB0 in the PLC online view.
8. Document. Save a copy of the final systemconfiguration.ini to the machine documentation directory and add a note to the project's configuration change log.

9. Verification Checklist

After commissioning, run through the following to confirm correct hardkey behavior:

10. Troubleshooting Matrix

Common issues encountered when configuring OP 010 hardkeys via systemconfiguration.ini:

11. Reference Documentation

The authoritative Siemens documentation for SINUMERIK 840D sl operator panel configuration is the Guide for the SINUMERIK 840D sl machine configuring, available from Siemens Industry Online Support. The manual contains the full INI section reference, the complete hardkey address map for the OP 010, OP 010C, OP 010S, OP 015, and OP 019 panels, and worked examples of OEM key remapping projects.

When evaluating the INI sections or PLC interface addresses cited in this article against the live machine, always cross-check with the project-specific configuration that the machine builder supplied. Standard Siemens defaults apply only to projects generated from the standard machine configuration templates; customized projects (especially retrofits) frequently remap DB19 to a different DB number.