WinCC Line Layout for Alarm Logging RT Message Sequence Reports

Overview

WinCC Alarm Logging Runtime ships a fixed-format Line Layout named @CCAlgRtSequence.RP1 that drives the print job Report Alarm Logging RT Message Sequence. The layout is intended for character-cell line printers connected to the station's parallel (LPT) port, and it is auto-activated by the WinCC startup list function Message Sequence Report. Whenever Alarm Logging Runtime queues an event, the layout emits one formatted line to the configured line printer queue.

Modern stations rarely expose an LPT port. The most common field situation is a USB-connected line printer (Epson TM-series, Star Micronics SP-series, OKI ML-series) or a USB-connected page printer being repurposed as a sequential event logger. This article documents how the .RP1 line layout works, how to re-route it to a USB device, and how to substitute or extend it with a Global Script C action when the built-in layout is too restrictive.

Architecture: Alarm Logging RT, Print Jobs, and Line Layouts

WinCC separates the alarm data path from the print path through three coordinated objects:

• Alarm Logging Runtime (CS/RT) — the message archive and event source. The RT component evaluates incoming tags, OPC alarms, or system messages and pushes events into the active message buffer.
• Print Job — a named configuration entry under WinCC Explorer > Report Designer > Print Jobs. A print job binds a layout file to a Windows print queue and a trigger (time, event, hotkey).
• Line Layout (.RP1) — a fixed-column text layout, one event per line, optimized for line printers. The counterpart Page Layout files use the extension .RPL and target page printers.

The runtime entry @CCAlgRtSequence.RP1 belongs to the system layout set delivered with every WinCC installation. It is referenced by the print job @Report Alarm Logging RT Message Sequence and is selected by the startup-list function Message Sequence Report. Removing or renaming the file disables the function silently because the startup list call is by string name.

Prerequisites

1. WinCC V7.x or WinCC Professional (TIA Portal) with Alarm Logging Runtime licensed and activated on the engineering station or a dedicated OS server.
2. The Windows printer driver installed and a working Windows print queue named consistently across reboots (avoid dynamic names like EPSON TM-T20 (Copy 2)).
3. For LPT-style logging on USB hardware, an active net use LPT1 mapping established before WinCC Runtime starts.
4. For scripted printing, Global Script Runtime with C interpreter enabled (default in WinCC V7).
5. Read/write permission to <WinCC project>\Print for layouts and to <WinCC project>\ScriptLib for action libraries.

The @CCAlgRtSequence.RP1 Line Layout File

An .RP1 file is a plain-text column definition. Each line in the file declares one output column for one event row. The runtime concatenates columns in declaration order until the line reaches the printer's width (commonly 80, 96, 120, or 136 columns). The default sequence report layout defines the columns shown below; field widths are characteristic for a 132-column line printer:

If the runtime encounters a column whose source value exceeds the declared width, it truncates by default. Some WinCC builds support a Wrap flag in the column properties that inserts a CR/LF and continues on the next line; this is undesirable for line printers because it desynchronizes the printed log from the audit trail.

Step-by-Step Configuration of the Print Job

1. Open WinCC Explorer on the engineering station and load the runtime project.
2. Right-click Report Designer > Print Jobs and select New Print Job. Name it exactly Report Alarm Logging RT Message Sequence if you are creating a project-local override; the system print job is identified by this string.
3. In the print job properties, set the Layout field to the user copy UserAlgRtSequence.RP1 (or @CCAlgRtSequence.RP1 for stock behavior).
4. Set the Printer dropdown to the desired Windows queue. For raw line printing, choose the queue with Print directly to the printer enabled and spooling disabled.
5. Open the Properties > Trigger tab. Enable Event-driven and bind to the Alarm Logging event source ALG.
6. Compile and download the project. Verify the new Print.ini entry: [Print] should contain RP1=UserAlgRtSequence.RP1 under the alarm section.
7. Start Runtime. The first queued alarm should print within one polling interval of the Alarm Logging service.

Mapping LPT1 to a USB Printer

The legacy @CCAlgRtSequence.RP1 layout emits raw bytes to whatever queue the print job points at. WinCC stores the queue assignment per project in <project>\Print\Print.ini. If the project still references the legacy parallel device LPT1, redirect with one of the following methods.

Method 1 — Windows Print Sharing (Persistent)

1. Share the USB printer on the WinCC station as AlarmPrinter with the share name AlarmLP.
2. From an elevated command prompt, run:
   net use LPT1 \\<hostname>\AlarmLP /persistent:yes
3. Restart the WinCC Runtime service. Confirm with net use that the LPT1 mapping persists across logon.

Method 2 — Windows Printer Pool (No Network Share)

1. Open Devices and Printers > Add a printer > The printer that I want isn't listed > Add a local printer.
2. Select Create a new port > Local Port and enter the UNC path \\<hostname>\AlarmLP.
3. Complete the wizard using the USB printer's driver. The local port appears in the print queue properties and accepts raw text the same way LPT1 would.

Method 3 — Direct Reassignment in Print.ini

Edit <project>\Print\Print.ini while Runtime is stopped. Replace the legacy device reference:

[AlarmLoggingRT]
Printer=AlarmLP
Layout=UserAlgRtSequence.RP1
Format=RP1

Save the file, restart the Alarm Logging service, and verify the assignment with type Print.ini.

Printing Multiple Alarms via Global Script C

When the operator wants a per-shift summary rather than a one-line-per-event stream, or when the printer only supports USB page-mode output, the recommended pattern is to suppress the system print job and emit a custom report from a Global Script C action.

Action: Dump All Pending Alarms to a USB Printer

1. Open WinCC Explorer > Global Script > C-Editor.
2. Create a new action of type Print Job / Project Function named PrintAlarmBatch.
3. Insert the following body, adapted from the Siemens WinCC V7 Global Script reference:

#include "apdefap.h"
void PrintAlarmBatch(const char* lpPrinterName)
{
    DWORD dwFlags = 0x0000;       // no time/status filters
    long  lMsgCount = 0;
    CMN_ERROR  Error;
    memset(&Error, 0, sizeof(Error));

    // Get the snapshot of currently active alarms
    lMsgCount = MSRTGetMsgCount(dwFlags, NULL, NULL);

    for (long i = 0; i < lMsgCount; ++i)
    {
        MSG_RTDATA_STRUCT msg;
        memset(&msg, 0, sizeof(msg));
        if (MSRTGetMsg(&msg, i, dwFlags, NULL, NULL) == 0)
        {
            char szLine[256];
            _snprintf_s(szLine, sizeof(szLine),
                _TRUNCATE,
                "%02d.%02d.%04d %02d:%02d:%02d  %c  P%-2d  %-12s  %-10lu  %-24s  %s\r\n",
                msg.stMsg.wDay, msg.stMsg.wMonth, msg.stMsg.wYear,
                msg.stMsg.wHour, msg.stMsg.wMinute, msg.stMsg.wSecond,
                (msg.dwMsgState == MSG_STATE_CAME) ? '+' : '-',
                msg.stMsg.wPriority,
                msg.stMsg.szClassName,
                msg.stMsg.dwMsgNumber,
                msg.stMsg.szSource,
                msg.stMsg.szText);

            // Raw write to the named printer queue
            HANDLE hPrinter;
            if (OpenPrinter((LPSTR)lpPrinterName, &hPrinter, NULL))
            {
                DOC_INFO_1 di = { (LPSTR)"AlarmBatch", NULL, (LPSTR)"RAW" };
                DWORD dwJob = StartDocPrinter(hPrinter, 1, (LPBYTE)&di);
                if (dwJob)
                {
                    StartPagePrinter(hPrinter);
                    DWORD dwWritten = 0;
                    WritePrinter(hPrinter, szLine, (DWORD)strlen(szLine), &dwWritten);
                    EndPagePrinter(hPrinter);
                    EndDocPrinter(hPrinter);
                }
                ClosePrinter(hPrinter);
            }
        }
    }
}

4. Add a button on the alarm view that calls PrintAlarmBatch("AlarmLP").
5. Disable the system print job Report Alarm Logging RT Message Sequence in the WinCC startup list to avoid duplicate output.

Switching from Line Printer to Windows Printer

If the station no longer has a continuous-feed printer and the operator only needs on-screen acknowledgement plus a Windows print spool archive, replace the line layout with a page layout:

1. In WinCC Explorer, navigate to Report Designer > Page Layouts and create UserAlgRtSequence.RPL.
2. Add a dynamic table bound to the Alarm Logging connection ALG; set the time range to Last 1 hour for a default shift report.
3. Edit the print job and replace the layout reference from UserAlgRtSequence.RP1 to UserAlgRtSequence.RPL.
4. Select a Windows print queue that supports RAW or EMF pass-through. EMF is preferable when using a laser printer because the spooler can re-paginate.
5. Trigger the job manually with the hotkey configured on the print job's Hotkey tab.

Verification and Test Procedure

1. Force a known alarm by toggling the configured trigger tag in the PLC or via Tag Simulation in WinCC.
2. Confirm the message appears in the Alarm Logging on-screen view within 500 ms.
3. Confirm one line is printed at the target queue within the next polling interval (default 1 s).
4. Repeat with a GO (clear) event; the column State should show '-'.
5. Disconnect the printer queue and observe whether Alarm Logging drops the event, queues it, or surfaces an error in WinCC Alarm Logging Diagnostics. Expected behavior is event buffering with no Runtime stop.
6. Restart the station and confirm the LPT1 mapping (Method 1) or local port (Method 2) is restored before WinCC Runtime initializes.

Troubleshooting Matrix

Performance and Sizing Notes

A single line printer can absorb roughly 800 to 1,200 lines/minute depending on character density and serial-vs-parallel transport. Burst alarm rates above this threshold will back up the WinCC print spool. Alarm Logging Runtime buffers up to 1,000 unprinted messages in the queue; overflow messages are written to <project>\Logs\AlarmLog.bak with a timestamp. Plan the alarm class structure so that high-frequency nuisance alarms (e.g. communication retries) are filtered from the sequence report before they hit the printer.

For USB thermal printers the realistic throughput drops to 250 to 400 lines/minute because of USB latency and FIFO buffering at the controller. If the alarm class exceeds 100 events/minute sustained, switch from line logging to periodic page-logging instead.

Migration Checklist from Legacy LPT to USB

1. Inventory every project print job that references an LPT device.
2. Map each LPT device to a named local port or persistent share.
3. Replace any direct LPT references in startup-list functions with the Windows queue name.
4. Run a 24-hour soak test with the alarm simulator generating 10 events/minute.
5. Validate the audit trail matches the printed log byte-for-byte.
6. Update the plant documentation: the printer is no longer a hardware asset of the PLC panel; it is a peripheral of the WinCC station.

FAQ