Resolving TP177A WinCC Flexible Transfer Timeout Error Image

Problem Overview

The Siemens SIMATIC TP177A 6" touch panel (order number 6AV6 642-0AA11-0AXA) is delivered from the factory with a runtime image that, in some early production lots, prevents a clean project transfer from WinCC flexible Compact 2005 SP1 / V1.1. The engineering tool reports "A timeout error occurred while receiving the files." while the panel itself freezes on "File 2 of 2." The transfer appears to start cleanly ("File 1 of 2" arrives in approximately 1 second) and then hangs during the second compressed runtime file (*_conv.srt).

This is not a cable, baud rate, or COM port failure. The root cause is a corrupt / mismatched factory image on the panel, and the documented fix is an OS / image update (bootstrapping) using the same RS-232 point-to-point link that is used for project transfer.

Affected Hardware and Software Identification

Reference: TP 177A / TP 177B / OP 177B (WinCC flexible) Operating Instructions, Release 07/2005, manual number 6AV6691-1DG01-0AB1, chapter 7.3 covers operating system restore / bootstrapping.

Symptom Matrix and Error Message Reference

Root Cause Analysis

Each TP177A ships with a Windows CE-based runtime image stored in flash. The image version is exposed in Control Panel → OP → Device → Image and the bootloader version is exposed one row above as Bootl. Rel.Date. A production run of the 6AV6 642-0AA11-0AXA was shipped with image 01.00.00.01_52.52 on top of bootloader 1.6 (2005-05-04). The header / descriptor block of that image rejects the runtime files generated by WinCC flexible Compact 2005 SP1 when the second (_conv.srt) payload is offered.

The panel still accepts the first ORIE_conv.cnk file (which carries the orientation descriptor and a small set of fonts), but stops acknowledging the larger compressed screen database. Because the protocol is master-slave with the engineering PC as master, the PC waits one transfer watchdog cycle (25 s in WinCC flexible Compact 2005) and then aborts with the timeout error.

Siemens' own resolution path is a full image update that replaces 01.00.00.01_52.52 with 01.00.00.02_05.58, which carries the corrected runtime header and acceptance logic for the SRT payload produced by WinCC flexible Compact 2005 SP1.

Pre-Update Verification Checklist

1. Confirm the panel boots and shows the Transfer dialog after a power-cycle — if not, the panel is hard-defective, not image-defective.
2. Read the image version: Control Panel → OP → Device → Image. If it already reads 01.00.00.02_05.58 or higher, the image is not the cause; investigate the cable, the COM port, or the COM port driver.
3. Read the bootloader version. The image 01.00.00.02_05.58 requires bootloader 1.6 or higher. If the bootloader is older than 1.6, run a two-stage update (bootloader first, then image).
4. Validate the cable on a known-good panel (TP 177 micro, TP 170B color) using ProSave V7.2 — successful backup/restore on a different panel proves the cable, COM port, and PC are not the fault.
5. Validate the cable order number: 6ES7 901-3CB30-0XA0 (RS-485 ↔ RS-232 PC adapter) is the only cable documented for serial transfer to the TP177A in the 07/2005 manual.
6. Try a fresh WinCC flexible project with a single screen and a single button. The error reproduces even on a 24 KB project, which proves the failure is independent of project size.
7. Try MPI transfer if available. MPI will not bypass the image mismatch, but it eliminates the cable / baud-rate axis from the diagnostic matrix.

Step-by-Step Image Update (Bootstrapping)

1. Download the TP177A image package for bootloader 1.6 from the Siemens support entry 21084461. The package contains a .img file and a matching .bin descriptor.
2. Power-cycle the panel. During the boot phase, watch for the Loader screen. Touch Control Panel → Transfer and verify that Channel 1 Serial is enabled and that the password protection is disabled (or note the password — the loader does not ask for it, but ProSave does on later transfers).
3. Close the loader back to the Transfer dialog. The panel is now waiting for an incoming project / image.
4. On the PC, start ProSave V7.2 (Start → SIMATIC → ProSave → ProSave). Configure the connection: Device type = TP177A, Connection = Serial, COM port = COM1 or COM2, Baud rate = 115 200 (use the lowest rate that the cable supports if 115 200 is unreliable).
5. In ProSave, choose OS → Update OS (German: Betriebssystem aktualisieren). Browse to the .img downloaded in step 1. ProSave will prompt to confirm the panel type and the current image version.
6. ProSave powers the panel into the bootloader (it does not require a manual power-cycle), erases the flash, and writes the new image. The panel screen goes blank except for a status line; the Output window in ProSave shows progress in 5% steps.
7. When the update completes, the panel reboots automatically into the loader. Open Control Panel → OP → Device and verify the Image field now reads 01.00.00.02_05.58 and the Bootloader is still 1.6.
8. Reboot the panel once more to be sure. The TP177A must come back to the Transfer dialog with no errors.

Post-Update Verification

1. Re-open WinCC flexible Compact 2005. Load the test project with a single screen and a single button. Confirm in Output that the build succeeds with 0 error(s), 0 warning(s).
2. Start the transfer with the same Transfer Settings that previously failed: Serial, COM1 or COM2, 115 200 baud. Watch the Output window: File 1 of 2 should be followed in well under 25 s by a successful File 2 of 2 completion line and an Transfer finished message.
3. Watch the panel: it should advance from File 1 of 2 to File 2 of 2, show the progress bar moving, and then either restart the runtime automatically or display the start screen of the project.
4. Confirm the runtime project is actually executing: a tag toggle from the connected S7-300 CPU 314 should change a value on the HMI screen within the configured polling cycle (default 1 s).
5. Run ProSave V7.2 → Backup to capture the working image. Save the backup to a dated folder — this is the recovery point for any future fault.

Compiler Output Decoded

The Output window in WinCC flexible during the failing transfer is a useful diagnostic. The two *_conv files are the deliverable payload: Device_1.ORIE_conv.cnk (orientation / header) and Device_1_conv.srt (compressed screen database). The byte-sequence and reference rewrites that the compiler performs are normal and are visible in the Output window between 18:01:42.26 and 18:01:42.32.

The fault pattern to recognize is:

• Time from File 1 of 2 is being transferred ... to File 2 of 2 is being transferred ... < 2 s → successful flow into SRT transfer.
• Time from File 2 of 2 is being transferred ... to A timeout error occurred ... ≈ 25 s → transfer watchdog fires while the panel holds the SRT payload unacknowledged.
• Total used memory of 24864 bytes (incl. 11 326 bytes for fonts) on a 524160 byte flash → project is not near the flash size limit, so the failure is not a flash-overflow issue.

Troubleshooting Matrix

Field Notes and Preventive Measures

• Always check the panel Image string on a brand-new panel before the first project transfer. A 10-second read of Control Panel → OP → Device saves an hour of cable / baud / project debugging.
• Document the working image version on the panel rating-plate label with a permanent marker. Panels that survive a board swap often come back with the original bad image.
• Back up the panel image with ProSave V7.2 immediately after a successful image update. The backup is a single file and recovers a bricked panel in under five minutes.
• For a fleet rollout, image-update every panel at receiving inspection. Do not assume that a panel that comes in the same shipping carton as the cable and CD is fit for use.
• The manual reference chapter for the OS restore is 7.3 of the 6AV6691-1DG01-0AB1 Operating Instructions, Release 07/2005. The same chapter covers the bootloader update.

Related Configuration Parameters

FAQ