Siemens OP17-PP ProTool Transfer Fails on MPI/DP Networks

Problem Overview

A Siemens OP17-PP operator panel (Siemens part number 6AV3 617-1JC00-0Ax1) refuses to accept a ProTool/Pro project whose driver is configured for MPI or PROFIBUS-DP multipoint coupling. The transfer stalls, aborts silently, or returns a generic "Transfer error" dialog. The cause is a hardware-level protocol mismatch, not a configuration mistake: the OP17-PP firmware implements only point-to-point serial protocols (AS 511, 3964R, and raw RS232/RS485), and the silicon does not include the PROFIBUS-DP controller required to attach to an MPI/DP bus as a node.

The same project compiles and transfers correctly to an OP17-DP variant. The mismatch is exposed at the moment of transfer, after ProTool/Pro has compiled the runtime container and only discovers the panel type when the OP17 boot loader reports its protocol capability during handshake.

Affected Hardware Identification

The SIMATIC OP17 is a 4-line × 20-character text-display HMI with membrane keypad, available in two communication variants. Identify the installed variant before any diagnostic work.

The two variants share identical front panels, cutout dimensions, mounting depth, and keypad layout. The differentiation is internal: the OP17-DP integrates a PROFIBUS-DP controller (typically an SPC3 or LSPM2 ASIC family member) and exposes a 9-pin Sub-D connector; the OP17-PP integrates a generic UART/serial controller and exposes two 15-pin Sub-D connectors. The hardware is otherwise common: same LCD, same keypad matrix, same microcontroller, same flash memory layout, same boot loader sequence.

The suffix is the only reliable physical differentiator. "-PP" denotes Point-to-Point; "-DP" denotes Decentralized Periphery (PROFIBUS-DP/MPI capable). Engineers familiar with the SIMATIC naming convention can read the part number at a glance, but the on-site check is the port layout: two 15-pin ports means OP17-PP, one 9-pin port means OP17-DP.

Root Cause Analysis

The OP17-PP was designed in the early 1990s for the AS 511 serial protocol used with the S5 and early S7-200 PLC families, and for the 3964R protocol used with CP340/CP341 communication processors on the S7-300/400. It does not contain a PROFIBUS-DP slave ASIC, and the OP17 firmware has no DP stack code. When ProTool/Pro compiles a project with the MPI/DP driver, the resulting runtime image includes:

• PROFIBUS bus parameter table (baud rate, slot time Tsl, minimum and maximum station delay min Tsdr / max Tsdr, gap factors, max retry limit)
• Configured PROFIBUS node address (1–126, where 0 and 126 are reserved for class-2 master diagnostics)
• Master/slave negotiation sequences and token-passing state machine for MPI
• DP-V0 cyclic I/O configuration, including slot mapping and I/O byte counts

The OP17-PP boot loader receives this image, attempts to initialize its (absent) DP controller, fails, and aborts. The visible symptom varies by ProTool/Pro version and transfer method:

All four symptoms trace to the same root cause: the project carries a DP bus parameter block that the OP17-PP hardware cannot interpret. The error is deterministic — every OP17-PP will fail on every project with an MPI/DP driver — but the visible message varies by ProTool/Pro revision and by the exact state of the OP17 boot loader when the abort occurs.

OP17 Boot Loader and Transfer Sequence

Understanding the boot loader sequence clarifies why the failure appears at transfer time, not at compile time.

1. The OP17 powers up with the boot loader active. The boot loader displays a version string and waits for a transfer on the configured port.
2. ProTool/Pro sends a bootstrap sequence at the configured baud rate (default 19,200 bit/s for serial transfers, 1.5 Mbit/s for MPI/DP transfers). The bootstrap is a short fixed-length packet that identifies the panel type and protocol.
3. The OP17 boot loader replies with its identity block, which includes a 16-bit protocol capability field. The OP17-PP reports 0x0001 (serial only); the OP17-DP reports 0x0003 (serial + MPI/DP).
4. ProTool/Pro checks the capability field against the project's configured driver. If the project is configured for MPI/DP and the panel reports 0x0001, ProTool/Pro aborts the transfer with the error dialog shown above.
5. If the capability check passes, ProTool/Pro streams the compiled runtime image to the OP17 in 1 KB blocks. The OP17 writes each block to flash, then signals readiness for the next block.
6. After the full image is received, the OP17 reboots into the new runtime.

Diagnostic Procedure

Run this sequence before changing project settings or swapping hardware. The goal is to positively identify the installed variant and the active ProTool driver.

1. Read the rating plate. Power down the panel and inspect the silver label on the rear. The full Siemens part number is printed in the form 6AV3 617-1JCxx-0Ax1. The xx group is the variant differentiator: JC00 = OP17-PP, JC20 = OP17-DP. The trailing 0Ax1 encodes the firmware revision and export version; this string does not change the protocol capability.
2. Inspect the back-panel ports. The OP17-PP has two 15-pin Sub-D ports labeled IF1A and IF1B. The OP17-DP has a single 9-pin Sub-D port. If you see two 15-pin ports, the unit is an OP17-PP by physical constraint.
3. Check the OP17 setup menu. Apply power and enter the setup menu. The exact key sequence depends on the firmware revision, but the typical entry is MENU + ENTER held during power-up. Navigate to Information > System. The reported interface type confirms the protocol capability. The setup menu also reports the firmware version; record it for support reference.
4. Open the ProTool/Pro project. In the project tree, select the panel node and read the Transfer Settings > Driver field. If the value is MPI or PROFIBUS-DP and the panel is an OP17-PP, the mismatch is confirmed.
5. Verify the CPU interface. In STEP 7 (or TIA Portal for newer projects) Hardware Configuration, locate the CPU 315-2DP. The CPU 315-2DP exposes two integrated interfaces: MPI/DP (X1) and DP (X2, where fitted). The OP17-PP cannot attach to either without a converter; the OP17-DP attaches directly to either using the MPI or DP protocol respectively.
6. Check the diagnostic buffer. On the CPU, read the diagnostic buffer (STEP 7 > PLC > Diagnostic/Setting > Diagnostic Buffer). Look for entries related to PROFIBUS or MPI: "DP slave not found", "Bus fault", or "Address conflict". These confirm that the bus is correctly configured but the OP17-PP is not responding as a slave.

Resolution Path A — Reconfigure the Project for Point-to-Point

If the application architecture allows one panel per CPU and the topology does not require multi-drop RS485, reconfigure the ProTool/Pro project to use a serial driver supported by the OP17-PP. The CPU 315-2DP does not have a native AS 511 or 3964R port, so a converter is required to bridge MPI/DP to the OP17-PP's serial interface.

Step-by-step ProTool/Pro reconfiguration:

1. Open the project in ProTool/Pro (or ProTool/Pro RT).
2. Select the panel node in the project tree and open Properties > Transfer > Settings.
3. Change the driver from MPI or PROFIBUS-DP to Serial.
4. Select the sub-driver appropriate to your converter and CPU side:
   • AS 511 — used with S7-200 or with S7-300 through an external AS 511 gateway.
   • 3964R — used with S7-300/400 through a CP340 or CP341 communication processor.
5. Set the baud rate. Typical values: 9,600 bit/s for AS 511, 19,200 bit/s for 3964R. The OP17-PP supports up to 38,400 bit/s on IF1A in RS232 mode and up to 187.5 kbit/s on IF1B in RS485 mode.
6. Set parity, data bits, and stop bits. The OP17-PP default for AS 511 is 8E1; for 3964R it is 8N1 with XON/XOFF flow control.
7. Assign the physical port: IF1A (RS232) for short runs under 15 m, IF1B (RS422) for longer runs up to 1,200 m at reduced baud.
8. Recompile the project (Project > Compile > All or the keyboard shortcut for compile).
9. Connect the OP17-PP to the PC, enter transfer mode on the panel, and transfer the project from ProTool/Pro.

Converter options for OP17-PP + CPU 315-2DP:

Resolution Path B — Replace the OP17-PP with an OP17-DP

If the application requires multi-drop MPI/DP (multiple panels on one bus, or a panel sharing the bus with distributed ET200 stations), replace the OP17-PP with an OP17-DP. The form factor is identical: same front bezel, same panel cutout (typically 198 × 142 mm for the OP17 family), same mounting depth, same power connector. The swap is mechanical and electrical drop-in.

Replacement procedure:

1. Power down the panel and the S7-300 station. Lock out and tag out the 24 VDC supply per local electrical safety practice.
2. Disconnect the serial cable(s) from the OP17-PP. Note which port carried which signal (IF1A or IF1B).
3. Release the four mounting clamps at the corners of the panel bezel. Use a flat-blade screwdriver; do not apply excessive force to the plastic tabs.
4. Withdraw the OP17-PP from the cabinet cutout, taking care not to snag the power supply cable or any rear connectors.
5. Verify the OP17-DP is in good condition and that the part number on its rating plate matches the OP17-DP variant in the family.
6. Insert the OP17-DP into the same cabinet cutout. Confirm the rear gasket seats evenly and the bezel sits flush against the cabinet surface.
7. Tighten the four corner clamps to approximately 0.5 Nm each. Do not over-tighten; the plastic bezel will crack.
8. Connect the PROFIBUS-DP cable to the 9-pin Sub-D port on the OP17-DP. Use a standard PROFIBUS connector with integrated termination switch. Enable termination on the connector at each end of the bus segment and disable it on connectors between.
9. Apply 24 VDC power. Enter the OP17-DP setup menu and set the PROFIBUS node address to a value not already used on the segment. The CPU 315-2DP default address is 2. The OP17-DP can occupy 1–126, but reserve 0 and 126 for class-2 master diagnostics if used.
10. Set the OP17-DP baud rate to auto-detect (default) or to the configured segment baud (1.5 Mbit/s is typical for CPU 315-2DP segments under 200 m).
11. Transfer the original ProTool/Pro project unchanged. The project was already configured for MPI/DP and the OP17-DP runtime accepts the DP bus parameter block.

Resolution Path C — Migrate to a Successor Panel

The OP17 is a legacy product and is no longer in the active Siemens catalog. For new installations, retrofit projects with long life-cycle expectations, or installations where the OP17 has failed and no spare is available, migrate to a modern successor. The recommended replacements, in increasing capability, are:

Migration procedure:

1. Export the ProTool/Pro project to a WinCC flexible import file: File > Export > WinCC flexible. This produces an archive containing the project files and tag database.
2. Install WinCC flexible (TIA Portal version for modern panels, or WinCC flexible 2008 for OP 77B and similar).
3. Create a new project, target the successor panel, and import the legacy project: Project > Import > ProTool/Pro in WinCC flexible, or Migrate project in TIA Portal.
4. Resolve any tag mapping warnings. ProTool tags are mapped to PLC symbols; the S7-300 symbol table must be re-imported if the tag names changed since the original ProTool project was last synchronized.
5. Recompile, transfer to the new panel, and verify per the checklist in the section below.

ProTool/Pro Driver Configuration Matrix

Use this matrix as the authoritative reference for selecting the correct ProTool/Pro driver for each combination of OP17 variant and CPU interface.

Cable and Wiring Reference

Cable selection depends on the resolved configuration. The OP17-PP and OP17-DP use different physical connectors and signaling standards; using the wrong cable is a common source of "no transfer" symptoms.

OP17-PP serial cables

The OP17-PP exposes two 15-pin Sub-D female ports. The signal mapping for the standard OP17-PP pinout is:

For a CPU 315-2DP via a converter, use a standard RS232 null-modem cable (crossover of pins 2 and 3, plus 4↔5, plus 7 to 7) between the OP17-PP IF1A port and the converter's PC-side or serial port. Maximum cable length for RS232 at 19,200 bit/s is 15 m. For longer runs, switch to RS422 on IF1B and use a shielded twisted-pair cable with 220 Ω termination at each end.

OP17-DP PROFIBUS cable

The OP17-DP uses a standard 9-pin Sub-D female PROFIBUS-DP connector with the canonical PROFIBUS pinout. The cable is the standard violet PROFIBUS cable (type A, per IEC 61158) with a twisted pair and a shield/drain wire. Maximum segment length depends on baud:

Each bus segment must be terminated at both ends with the PROFIBUS standard termination: 220 Ω in series between the two data lines, plus 390 Ω pull-up to +5 V on one line and 390 Ω pull-down to ground on the other. PROFIBUS connectors with integrated termination switches implement this internally; activate the switches only on the two end nodes of the segment.

OP17 Diagnostic and Status Indicators

The OP17 reports its operating state through a combination of on-screen messages and front-panel LED behavior. Use the following table to interpret the panel's status during commissioning.

STEP 7 Integration Notes

When commissioning an OP17-PP on a CPU 315-2DP via a converter, the S7 program does not need to be modified — the OP17 reads/writes tags from the CPU's process image and data blocks, and the converter is transparent to the application. The CPU sees the converter as a peer, and the OP17-PP sees the converter as a CPU.

When commissioning an OP17-DP, the DP slave must be present in the STEP 7 hardware configuration:

1. Open the S7 project in STEP 7 (or TIA Portal for newer projects).
2. Open HW Config and locate the PROFIBUS-DP master (the CPU 315-2DP's DP port or an external CP).
3. Drag the OP17-DP from the SIMATIC HMI catalog into the PROFIBUS-DP subnet.
4. Set the OP17-DP's node address to match the physical panel.
5. Configure the slots: at minimum, slot 0 (the OP17 itself) and slot 1 (the operator panel data area) need to be defined for consistent DP communication. The exact slot definition depends on the OP17-DP GSD file revision.
6. Save, compile, and download the hardware configuration to the CPU.

For a CPU 315-2DP with the OP17-DP on the integrated DP port (X2), the master configuration adds the OP17-DP as a DP slave. The CPU's DP master polls the OP17-DP cyclically for status and pushes tag updates. The OP17-DP's slot 0 is the device itself (diagnostics); slot 1 carries the operator panel data area (input and output bytes for tag data).

Tag addressing in ProTool/Pro:

ProTool/Pro tags are bound to S7 addresses in one of three ways:

• Absolute address: e.g., DB10.DBW0, I0.0, Q4.1. Direct mapping to the S7 address; no symbol table required.
• Symbolic address: e.g., Motor_1_Speed. Resolved through the S7 symbol table; the symbol table must be re-imported into ProTool/Pro whenever the STEP 7 program changes.
• PLC-typed tag: A tag with a defined data type (BOOL, INT, REAL, STRING) bound to an address or symbol. ProTool/Pro performs the type conversion automatically.

For a CPU 315-2DP, the process image is refreshed by the CPU at the start and end of each OB1 cycle. Tags read from the process image are always current; tags read from data blocks (DB) reflect the most recent value written by the S7 program. For a DP-attached OP17-DP, the tag data is exchanged cyclically between the CPU and the OP17-DP, with the cycle time determined by the PROFIBUS baud rate and the number of slaves on the segment.

Verification Checklist

Run this sequence after any configuration change or hardware replacement. Each step must pass before the system is returned to production.

1. Confirm the OP17 displays the configured startup screen with no error overlay.
2. Confirm the OP17's communication icon is steady (not blinking), indicating a healthy link to the CPU.
3. In ProTool/Pro, force a read-only tag (e.g., a process input or a status bit) to a known value using STEP 7's Monitor/Modify function. Verify the value appears on the panel.
4. Operate a write tag (e.g., a motor start pushbutton on the panel). Verify the corresponding bit in the CPU process image transitions to the expected state. Use STEP 7's Monitor function in online mode to confirm.
5. If the project contains alarm logging, trigger an alarm and verify it appears in the panel's alarm view with the correct timestamp and text.
6. Power-cycle the OP17 (24 VDC off for 10 seconds, then on). Verify the panel re-establishes communication within 30 seconds of the startup screen appearing.
7. Check the CPU's diagnostic buffer (STEP 7 > PLC > Diagnostic/Setting > Diagnostic Buffer) for any new communication-related entries. A clean diagnostic buffer is the strongest single signal that the configuration is correct.
8. Verify that no PROFIBUS diagnostic repeaters or bus monitors report segment errors (for OP17-DP configurations).
9. Verify the OP17's PROFIBUS node address matches the HW Config entry (for OP17-DP).
10. Verify the OP17's bus baud rate matches the configured segment baud (for OP17-DP).

Troubleshooting Matrix

Edge Cases and Field-Commissioning Notes

The following scenarios arise repeatedly in field service and are worth addressing explicitly.

Edge case 1: Third-party OP17-PP clones. Aftermarket OP17-PP panels from non-OEM vendors may report the wrong part number on the rating plate. Always verify the physical port layout (two 15-pin Sub-D ports = OP17-PP) before trusting the label. Clones may also have a different firmware revision that misreports its protocol capability to the boot loader. If a "new" OP17-PP rejects an MPI/DP project, the clone may actually be an OP17-PP hardware revision with broken DP firmware — not all clones are equal to the Siemens-original hardware. Where possible, source replacement OP17 panels from Siemens authorized distributors to avoid this risk.

Edge case 2: Mixed OP17-PP and OP17-DP on a segment. If an existing OP17-DP is on a PROFIBUS segment and a new OP17-PP is mistakenly added, the OP17-PP will not communicate regardless of the project configuration. The diagnostic symptom is a panel that never appears in the bus master's slave list. Resolve by removing the OP17-PP or replacing it with an OP17-DP. The PROFIBUS master will repeatedly report "slave not found" for the OP17-PP's address; this is a strong signal that the wrong panel type has been installed.

Edge case 3: Long cable runs with OP17-PP. The OP17-PP IF1B port in RS422 mode supports runs up to 1,200 m at 9,600 bit/s. At 38,400 bit/s, the maximum practical run is closer to 200 m due to signal skew on the RS422 differential pair. If the application requires longer runs at higher baud, plan for an OP17-DP on PROFIBUS rather than OP17-PP on serial. The PROFIBUS cable is also more rugged and better suited to industrial environments than the OP17-PP serial cable.

Edge case 4: Mixed firmware revisions on the same ProTool/Pro version. The OP17-PP and OP17-DP have distinct firmware images. ProTool/Pro versions V5.2 through V6.0 SP3 support both variants; older ProTool/Pro versions (V4.x and earlier) may not support the OP17-DP variant at all and may reject the project at compile time with a different error message. Verify the ProTool/Pro version supports the target panel before commissioning. Mixing ProTool/Pro SP revisions within the same project file is a common source of "works on one engineer's PC, fails on another's PC" symptoms.

Edge case 5: Power supply budget on the 24 VDC bus. The OP17 (both variants) draws approximately 250 mA at 24 VDC. The S7-300 CPU 315-2DP draws approximately 0.8 A at 24 VDC. If the existing 24 VDC supply is sized for the CPU alone and the OP17 is added, the supply may brown out during the OP17's inrush, causing the panel to reboot and fail to establish communication. Measure the 24 VDC rail under load before commissioning. A regulated supply rated for at least 2× the expected load is the standard safety margin.

Edge case 6: CP340/CP341 with 3964R on the OP17-PP. When using a Siemens CP340 or CP341 communication processor on the S7-300 side with the OP17-PP, configure the CP for 3964R protocol, set the baud rate to match the OP17-PP (default 19,200 bit/s), and assign a free logical port number in the S7 hardware configuration. The CP must be present in HW Config with a slot assignment, even if the S7 program does not use it actively; ProTool/Pro communicates with the CP via the S7 backplane bus, not via the application program.

Edge case 7: Converting an OP17-DP project to OP17-PP in the field. Engineers sometimes attempt to convert an OP17-DP project to OP17-PP by changing the panel selection in ProTool/Pro. This is not a driver conversion; the project still carries DP bus parameter blocks. The only way to make the project work on an OP17-PP is to reconfigure the driver to Serial (AS 511 or 3964R) and add a converter — the panel selection alone is cosmetic.

FAQ