Siemens Coros OP15 Program Transfer: ProTool and COMText Reference

The Siemens Coros OP15 is a text-based operator panel from the late 1980s / early 1990s generation of Siemens HMI hardware. It is long discontinued, yet a population of these units remains in service on legacy machines, predominantly paired with SIMATIC S5 and early S7 controllers. Because the OP15 pre-dates the modern WinCC / TIA Portal toolchain, all program transfer operations (upload, download, language change, configuration backup) must be performed with the era-appropriate configuration software: ProTool for firmware ≥ 2.2, or COMText for firmware < 2.2.

This reference consolidates the documented transfer procedures, the cable and protocol requirements, the firmware-to-software mapping, and the known field issues that affect OP15 program mobility. The procedures described here apply to the OP15-A1 variant and equivalent members of the Coros OP15 family. Where official Siemens support documentation exists, the canonical entry ID is referenced so the engineer can validate the procedure against the manufacturer's knowledge base before commissioning.

1. OP15 Hardware Variants and Firmware Identification

The OP15 family is a small footprint, monochrome (2-line or 4-line LCD) operator panel with a membrane keypad. Two sub-variants are commonly encountered in the field:

The firmware version is reported on the OP15 splash screen at power-up. If the unit powers up directly into the project screen, enter the system menu via the dedicated key combination (typically the upper-left softkey + the F key) to reveal firmware and project metadata. The firmware boundary at version 2.2 is significant: below that build, ProTool will not recognize the device, and only COMText can be used.

2. Required Software Stack

2.1 COMText (firmware < 2.2)

COMText is a DOS-based configuration tool. It was distributed on 3.5" floppy media and is the only tool that can talk to early OP15 firmware. The PC must run DOS, Windows 95, or a DOS window under Windows 98 with a real or virtual COM port. Modern Windows 10 / 11 hosts cannot run COMText natively; use a legacy PC, a DOS-boot VM, or a USB-to-serial adapter with a true 8250/16550-compatible UART profile. The tool stores the project in a *.ct file with a flat directory layout.

2.2 ProTool (firmware ≥ 2.2)

ProTool is the Windows-based HMI configuration suite that succeeded COMText. For OP15, the relevant ProTool version is ProTool / Pro CS or ProTool V6.x with the OP15 device driver. ProTool imports/exports *.pdz and *.pdb project files. ProTool Lite or ProTool / Pro RT may be used depending on what license is available.

2.3 Language Modules

Both tools support the language switching feature, but language resources are stored in the project and transferred with the configuration file. There is no separate "language file" on the OP15; changing the display language is a project re-compile and re-transfer operation, not a runtime toggle.

3. Hardware Interface and Cable Requirements

The OP15 communicates over a serial point-to-point link. Depending on the variant, the physical port is:

• TTY / 20 mA current loop (most OP15-A1 units) — 25-pin sub-D on the panel side.
• RS-232C (V.24) on later units — 9-pin sub-D on the panel side.
• MPI / PROFIBUS (rare) — via the SIMATIC MPI connector.

For a direct PC-to-OP15 link, the typical cabling chain is:

1. OP15 25-pin TTY port — Siemens TTY-to-RS232 converter cable (order code historically 6ES5 734-1xxx, availability limited to spare-part stock).
2. RS-232 from the converter — standard shielded serial cable — PC COM port (DB-9 male).
3. If the host PC has no physical COM port, a USB-to-RS-232 adapter must be used. Only adapters with FTDI or comparable industrial-grade 16550-compatible chipsets are recommended. Low-cost CH340-based adapters frequently fail the timing checks of the OP15 bootloader.

For a PC ↔ PLC ↔ OP15 path (configuration transferred via the PLC's MPI / AS511 port), a Siemens PC Adapter (MPI/USB, 6ES7 972-0CB20-0XA0) is inserted between the PC and the PLC. The OP15 itself remains on its own serial or MPI tap in this topology.

4. PC → OP15 Program Download (Configuration Push)

The download direction is the well-supported path. Use this procedure when commissioning a fresh OP15, restoring a panel from a known-good backup, or pushing a new language build.

4.1 With ProTool (firmware ≥ 2.2)

1. Open the project in ProTool. Verify the device selected in the project tree is OP15 (not OP17, OP25, or OP35 — the panel will reject an incorrect image).
2. Select File → Compile → All and resolve any compile errors. The OP15 has limited tag and screen memory; compile warnings on memory overflow must be cleared before transfer.
3. Connect the serial cable as described in Section 3. Power the OP15.
4. On the OP15, enter the system menu and select Transfer (or Download depending on language). The panel displays READY FOR TRANSFER or similar.
5. In ProTool, choose Target → Transfer → PC → Panel (Serial). Select the COM port (e.g., COM1) and the baud rate. The default OP15 baud is 9600 bps; do not exceed 19200 bps unless the specific firmware build supports it.
6. Initiate the transfer. ProTool reports progress and verifies the image after upload. A successful transfer ends with TRANSFER OK on the panel.
7. Cycle power to the OP15. The new project boots and displays the start screen.

4.2 With COMText (firmware < 2.2)

1. Launch COMText from the DOS prompt: CT <project.ct>.
2. From the File menu, choose Transfer → PC → OP.
3. Set the COM port and baud rate to match the OP15 transfer-menu setting.
4. Put the OP15 in transfer-ready mode from its system menu.
5. Execute the transfer. COMText shows sector-by-sector progress on the PC; the OP15 shows RECEIVING and a block counter.
6. When COMText reports Transfer complete, cycle OP15 power.

5. OP15 → PC Program Upload (Configuration Backup)

The upload direction is the fragile path and is the operation that creates the most support tickets. The OP15 was originally specified as a one-way configuration target: a project is authored on the PC and pushed to the panel. Reading a project back from the panel is supported in COMText and in ProTool, but the round-trip is not guaranteed to be lossless, and Siemens has historically recommended that the master project be stored on the PC rather than relying on the panel as the source of truth.

Additionally, the OP15 does not support cloning a backup image from one panel and writing that image into a different panel. Each panel is paired with its project; a panel-to-panel image copy will install the project but may render softkeys, alarms, or language entries incorrectly. This is documented in the official Siemens support entry 36389:

Siemens Support Entry 36389 — COROS OP15 softkeys no longer function after OP → FD → OP transfer

That entry states: "If, with an OP15, the configuration of OP → FD → OP is transferred, the softkeys no longer function." The workaround Siemens published is to transfer the configuration PC → OP rather than OP → FD → OP. The same class of corruption has been observed on direct panel-to-panel copies.

5.1 Upload with ProTool

1. Connect the OP15 to the PC as described in Section 3.
2. Put the OP15 into transfer mode from its system menu.
3. In ProTool, choose Target → Transfer → Panel → PC (or Upload). Select the COM port and baud rate.
4. ProTool reads the configuration and saves it as a project file. Confirm the resulting project compiles cleanly on the PC — if ProTool reports unresolved tag references or missing screen elements, the upload is partial and the original *.pdb on the PC remains the master.
5. Immediately back up the uploaded *.pdb to a versioned location; do not edit it in place.

5.2 Upload with COMText

1. Run CT and connect to the OP15 in transfer mode.
2. Choose Transfer → OP → PC.
3. Save the resulting project as a new *.ct file. Do not overwrite the existing on-PC master.
4. Open the uploaded project, compile, and diff against any known-good master if one exists.

5.3 What Upload Cannot Recover

• Comments and developer notes that were not compiled into the project binary.
• Project history and audit trail.
• Any post-build patches applied directly to the panel's flash.
• Softkey label maps in the corrupted case described in support entry 36389.

6. PC ↔ PLC ↔ OP15: Indirect Transfer via the PLC

When the OP15 is paired with a SIMATIC S5 or S7 PLC, the panel is normally configured as a slave device on the PLC's serial or MPI port. The PC can reach the OP15 by routing through the PLC, or it can be connected directly to the OP15. The route selection depends on cable availability and on whether the OP15 port is already pinned to the PLC.

The PLC and OP15 communicate using the protocol appropriate to the PLC generation: AS511 for S5, MPI for S7-200 / S7-300. ProTool/Pro and the COMText tools expect a matching protocol setting in the project; a mismatch between the project's protocol setting and the physical wiring is the single most common cause of TIMEOUT errors during transfer.

7. Language Change Procedure

The OP15 does not have a runtime language switch. To change the display language, the project on the PC must be re-authored with the new language text, recompiled, and re-transferred to the panel. Procedure:

1. Open the master project on the PC in ProTool or COMText.
2. Open the language table (in ProTool: Project → Languages → Edit). The OP15 supports up to 2 or 3 languages simultaneously depending on firmware build; the project must fit within flash memory after the new language table is added.
3. Enter the new-language translations for every visible text element: screen captions, alarm messages, softkey labels, system messages.
4. Set the runtime language (the language the panel will display at boot) in the project settings.
5. Recompile the project. Resolve any "text exceeds display width" warnings — English and German often have different string lengths and require layout adjustment.
6. Transfer PC → OP15 as in Section 4.
7. Verify the boot screen displays the new language. Verify alarm texts render correctly (truncation is a common defect on the 2-line variant).

8. Known Issues and Field-Proven Workarounds

9. Firmware Boundary at Version 2.2

The 2.2 firmware boundary is the single most consequential version detail on the OP15. Below 2.2, the panel exposes only the COMText transfer protocol; ProTool will not detect the device. At 2.2 and above, the panel exposes the ProTool transfer protocol and is incompatible with COMText. There is no in-the-field firmware upgrade path that is officially documented. If the on-PC master is lost and the on-panel firmware is below 2.2, the only viable recovery tool is COMText. If the firmware is at or above 2.2, ProTool is the only viable recovery tool. Engineering the wrong path wastes hours of debug time and risks a flash corruption if the bootloader's protocol expectations are violated.

10. Obsolescence and Migration

Siemens formally cancelled the Coros OP15 product line more than twenty years ago. Original software media, the COMText DOS distribution, and TTY-to-RS232 converter cables are no longer in production. The recommendation in the field, consistent with the position Siemens Support takes on these legacy panels, is to migrate the operator-interface function to a current SIMATIC HMI panel (SITOP or SIMATIC HMI Unified series) on the next scheduled outage. The migration preserves the SIMATIC PLC tag list and the alarm/control logic; the on-panel screens must be re-authored in TIA Portal or WinCC.

For installations where migration is not yet scheduled, the practical continuity measures are:

• Maintain a versioned on-PC master of the project for every OP15 in service.
• Store a working COMText or ProTool environment (including the DOS VM if applicable) under configuration management.
• Stock at least one verified TTY-to-RS232 cable and one FTDI USB-to-serial adapter per site.
• Label every OP15 with its firmware version, the tool used, and the PC master's storage path.

11. Verification Checklist After Any Transfer

1. Cycle OP15 power and confirm the new project boots to the configured start screen.
2. Verify the boot-time language matches the project setting.
3. Test every softkey; if any is non-responsive, suspect the OP → OP corruption pattern from entry 36389 and re-transfer from the PC master.
4. Trigger at least one alarm of each class; verify text and that the alarm is acknowledged cleanly.
5. Read three process tags from the live PLC and confirm the displayed values match the PLC's actual value (e.g., read from STEP 5 or STEP 7 directly).
6. Confirm write-back: change a setpoint from the panel, observe the value change in the PLC's online view.
7. Save the OP15 project state to a versioned PC location. The post-transfer PC master is the recovery point.

12. Frequently Asked Questions