WinCC Sequence Overview Screen: Step Text, Blocking Condition and Step History Lab Manual (V8.1)

• Step and wait code come from the PLC; WinCC turns them into text.
• One structure type, one row per machine.
• Archive transitions to find where time is lost.

Designing the Overview Screen

One row per machine: name, step text, blocking condition, step time against its limit, cycle count. Colour only for abnormal (a timeout), as in HMI screen design best practices. A click on a row opens the detail screen of that machine.

Lab Flow: From Station Sensors to a Line Overview

Every lesson in the Softwell PLC lab manual series follows the same six stages and the same address rule, so the code you write here plugs straight into the HMI lessons.

Stage 1Field Wiring and PLC Tags

Stage 2Input Mapping into DB_IO

// FC_InputMapping
"DB_IO".M1_PartPresent   := "M1_PartPresent";
"DB_IO".M1_Clamped       := "M1_Clamped";
"DB_IO".M1_Done          := "M1_Done";

Station 2 is mapped the same way.

Stage 3PLC Logic in Ladder and SCL

The same logic in SCL – use whichever your plant standard prefers; both write the same DB members that WinCC reads:

// FB_SeqM1 – CASE sequence with wait codes (see the TIA lessons for the full pattern)
#T_Step(IN := #Step = #StepOld, PT := #StepMax);
"DB_SeqM1".StepChanged := #Step <> #StepOld;      // ladder network 1 uses this
#StepOld := #Step;
CASE #Step OF
    10: IF NOT "DB_IO".M1_PartPresent THEN "DB_SeqM1".Wait := 1; ELSE #Step := 20; END_IF;
    20: IF NOT "DB_IO".M1_Clamped     THEN "DB_SeqM1".Wait := 2; ELSE #Step := 30; END_IF;
    30: IF NOT "DB_IO".M1_Done        THEN "DB_SeqM1".Wait := 3; ELSE #Step := 10; END_IF;
END_CASE;
"DB_SeqM1".Step := #Step;
"DB_SeqM1".MachineStep := #Step = 20 OR #Step = 30;
"DB_SeqM1".Timeout := (#T_Step.Q AND "DB_SeqM1".MachineStep) OR ("DB_SeqM1".Timeout AND NOT "DB_SeqM1".Cmd_Reset);

The complete pattern with hold, abort and recovery is in PLC step sequences.

Stage 4Link PLC Tags to WinCC: Structure Type

In Tag Management add the SIMATIC S7-1200, S7-1500 Channel, create a connection with the CPU IP address, then use AS Symbols to load the PLC symbols and drag the DB members you need into a tag group. The DB members must have Accessible from HMI ticked in TIA Portal. Names and menus can differ slightly between WinCC versions.

Create a structure type Seq with elements Step, Wait, StepTime, Timeout and Cycles, then instances M1 and M2 addressed to DB_SeqM1 and DB_SeqM2. A new machine is one more instance.

Stage 5Text Lists, Overview Screen and Step Archive

The panel version is in HMI sequence status screen.

Stage 6Perform and Test: Two-Machine Sequence Overview

Two stations run their sequences. The overview screen shows step text, blocking condition, step time and cycles; the history table is what the step-transition archive keeps. Jam a station and read the cause from the screen.

Troubleshooting