Configuring LOGO! 8 Pure Timer Values via KTP Basic Panel HMI

1. Overview: Remote Timer Adjustment on LOGO! 8 Pure Systems

The Siemens LOGO! 8 "Pure" variant is a logic-relay controller without an integrated display or operator keys. It is intended for cabinet-mounted, headless operation where parameter changes are made exclusively from external engineering tools or human-machine interfaces. When the system integrator selects a Pure variant to reduce panel cost and footprint, every operator-adjustable parameter — including on-delay (TON) timer setpoints, off-delay (TOF) durations, retriggerable pulse timers, and weekly / yearly timers — must be exposed through a remote interface.

The most common field topology pairs a LOGO! 8 Pure (for example, 6ED1052-1CC08-0BA0 or the FS:04 successor 6ED1052-1CC08-0BA1) with a SIMATIC KTP400 Basic, KTP700 Basic, KTP1000 Basic, or TP1500 Basic panel over the on-board Ethernet interface of the LOGO! 8 basic module. The KTP family runs WinCC Basic / TIA Portal projects and uses S7 communication to write directly into the LOGO! 8 variable memory (VM).

This reference documents the complete workflow: enabling Parameter VM Mapping inside LOGO!Soft Comfort, building the S7 connection inside TIA Portal, defining HMI tags that reference the LOGO! VM area, and wiring those tags to numeric I/O fields on the KTP screen. It also addresses time-base handling, TDE and Web-Editor alternatives, and a structured troubleshooting matrix for the connection faults most often encountered during commissioning.

2. LOGO! 8 Hardware Architecture and "Pure" Variant Identification

LOGO! 8 modules are shipped in two principal forms:

• LOGO! 8 with display (LOGO! ...B0) – front-integrated 6-line LCD and 6 cursor / 4 program keys; allows direct parameter edits through the on-board UI.
• LOGO! 8 Pure (LOGO! ...B0 "pure") – same logic engine, same I/O count, same communication ports, but no display, no keys, and a smaller front bezel. Operator adjustments must come from LOGO!Soft Comfort, the LOGO! TDE text display, the integrated Web server, or an external HMI.

Typical catalog references for the Pure family:

All variants share an identical Ethernet port supporting PROFINET, S7 communication (server role), and the integrated Web editor (HTML5). The Pure variant does not have reduced firmware features; it only lacks the local operator interface. This means VM mapping, S7 communication, and the Web editor operate identically across both flavors.

3. Variable Memory (VM) Fundamentals for Parameter Mapping

VM is a reserved, non-volatile memory area inside the LOGO! 8 controller that exchanges data with external partners. Three VM zones exist:

When a block parameter (such as the time constant of an on-delay timer) is assigned to a VM address through the Parameter VM Mapping tool, that value becomes readable and writable from outside the LOGO! logic. Without VM mapping, the parameter is internal to the program and cannot be reached from an HMI.

For timer blocks, the mapped VM word holds the time value expressed in the time base units that were selected on the block itself. A timer configured with time base = seconds and a VM-mapped value of 30 will produce a 30 second on-delay; the same VM value with time base = minutes yields a 30 minute on-delay. The time base is a block property and is set inside LOGO!Soft Comfort; the VM-mapped value only carries the numeric count.

4. Enabling Parameter VM Mapping in LOGO!Soft Comfort

Open the program in LOGO!Soft Comfort (V8.0 minimum; V8.1 or later recommended to open projects attached to community threads that target V8.1). Perform the following actions:

1. From the menu bar, choose Tools → Parameter VM Mapping. The Parameter VM Mapping dialog opens with a tabular list of every block parameter that can be exposed.
2. Scroll to the on-delay timer block you want to externalize (for example, B001 — On-Delay). Two parameters appear: the time constant (T) and the time base (TB).
3. Click the checkbox in the "VM" column next to the time constant. A small drop-down offers the next free VM word. The default suggestion is the lowest unused VW.
4. Note the address. For an on-delay timer near the top of the program, LOGO!Soft typically proposes VW0. Accept or override as required.
5. Optionally, tick the time-base row and bind it to a separate VM word (for example, VW2) if your HMI screen must let the operator change units as well. In most installations the time base is left locked, and only the time value is mapped.
6. Confirm with OK. The mapping is written into the program source and travels with the project file.
7. Save the project and download it to the LOGO! 8 Pure via Ethernet (PC ↔ LOGO! direct cable or via switch). The mapping becomes effective only after the program is running on the target.

5. Configuring the On-Delay (B001-type) Timer for HMI Exposure

Place the on-delay block on the FBD / LAD canvas in LOGO!Soft Comfort as you would for any internal timer:

1. Drag Special functions → Timers → On-Delay onto a free slot. The block number is assigned automatically; B001 is conventional for the first timer.
2. Open the block properties and set the time base. The available bases are:

3. Set an initial time value (for example, 6 seconds). This value is overridden by the VM-mapped address once the program runs and the HMI writes to the VM word.
4. After mapping, the time-value parameter is no longer authoritative inside LOGO!Soft; the VM word takes priority at runtime. Downloading the program still includes the editor value as a fallback in case the VM area is empty.
5. Repeat for any other timers, counters, or analog thresholds that the operator must change from the KTP.

6. KTP Basic Panel Hardware and TIA Portal Project Setup

The KTP Basic family runs on WinCC Basic and is configured inside the TIA Portal (V15.1, V16, V17, V18, or later). Panels compatible with the workflow below:

In TIA Portal:

1. Create a new project and add the LOGO! 8 device from the hardware catalog (Siemens → LOGO! → LOGO! 8 → Basic Modules → Pure → matching catalog number). This brings the LOGO! tag table into the project and pre-populates the standard VM and digital addresses.
2. Add the KTP Basic panel from the same catalog (SIMATIC HMI → KTP Basic → matching display size and firmware version).
3. Assign static IP addresses inside Device Configuration. Recommended convention: LOGO! = 192.168.0.10 / 24, KTP = 192.168.0.20 / 24. Confirm that the subnet mask matches on both devices.
4. Compile the LOGO! device and download its project so the VM mapping table inside the LOGO! controller matches the one inside TIA Portal.

7. Building the S7 Connection Between KTP and LOGO! 8

LOGO! 8 acts as an S7 server. The KTP acts as the S7 client. Inside TIA Portal:

1. Right-click Devices & Networks and select Connect devices → S7 connection*. The connection object is created and graphically drawn between the two ports.
2. Click the connection line and verify the parameters:

3. If the LOGO! device is not in the TIA project (third-party panel against an unknown LOGO!), use an unspecified S7 partner instead. Enter the LOGO! IP and use TSAP 02.01, rack 0, slot 1.
4. Compile and download both the LOGO! and the KTP projects. The KTP will attempt to establish the S7 connection immediately after reboot.

8. Configuring HMI Tags and Screen Objects for Timer Entry

Once the connection is online, create HMI tags that point to the VM words you exposed in Section 4.

1. Open the KTP's HMI Tags table.
2. Add a tag named Timer_OnDelay_B001_Time:

• Data type: Int (timer values fit in 16-bit signed integer).
• Connection: the S7 connection created in Section 7.
• Address: VW0 (the address assigned during VM mapping).
• Acquisition mode: Cyclic in operation, 1 s.
• Limits: 0 – 9999 (covers all LOGO! timer ranges).

3. Open the screen editor and drag an I/O Field onto the canvas.
4. Configure the field:
   • Mode: Input/Output
   • Tag: Timer_OnDelay_B001_Time
   • Display format: decimal, 4 digits
   • Behavior on invalid input: accept value
5. Add a static text label "On-Delay B001 (s)" beside the field so the operator knows the unit.
6. Save and download the HMI project to the KTP.

At runtime, typing a value into the field writes it directly into LOGO! VM address VW0. The LOGO! on-delay block reads that word on the next cycle and updates its internal elapsed-time comparator. Changes take effect within one LOGO! scan (typically 5–20 ms for a small program).

9. Time Base Handling and Conversion Considerations

The VM-mapped value is always expressed in the units of the time base that was selected when the block was created. The KTP I/O field is a raw numeric editor; it does not know about minutes, hours, or hundredths unless the integrator builds that logic explicitly. Two field-proven patterns are common:

Pattern A — Seconds-only HMI. Configure the on-delay block with time base = seconds (Base Code 2). Bind a single INT tag to VW0. The operator enters a plain number of seconds. This is the simplest case and is the one most projects ship with.

Pattern B — Mixed unit HMI. Map the time base to a separate VM word (VW2 in this example) and present two I/O fields on the screen — one for the value, one for the base selector. The base selector can be implemented as a symbolic I/O field with four options (10 ms, 100 ms, 1 s, 1 min). The KTP writes the integer code (0–3) into VW2; the LOGO! block reinterprets VW0 in the new unit. Edge case: the operator must understand that "10" with base = seconds means 10 seconds, while "10" with base = minutes means 10 minutes.

10. Alternative Input Paths: LOGO! TDE and Web-Based Editor

If a KTP Basic panel is not available, two other paths exist to write to the same VM area:

• LOGO! TDE (Text Display) — external 6-line LCD module wired to the LOGO! 8 over the dedicated TDE bus (not Ethernet). Catalog reference 6ED1055-4MH08-0BA0 for LOGO! 8 TDE. The TDE presents parameter lists and exposes any VM-mapped value, so it can serve as a low-cost operator panel.
• LOGO! Web Editor (HTML5) — open a browser to http://192.168.0.10 (default username LOGO, password LOGO on older firmware; FS:04 uses a per-device password). The Web editor exposes the same VM-mapped variables as configurable input fields, and the operator can type values from a tablet or laptop on the same subnet.
• LOGO!Soft Comfort online mode — from a PC connected over Ethernet, the Tools → Parameter VM Mapping window acts as a live editor. Useful during commissioning but not suitable for daily operation by non-engineers.

All three write to the same VM address and are mutually compatible with the KTP solution; the most-recent write wins until the next PLC scan completes.

11. Commissioning Procedure and Verification Checklist

1. Power the LOGO! 8 Pure and verify the RUN LED is solid green and the ERROR LED is off.
2. Connect the engineering PC to the LOGO! 8 over Ethernet. From the PC, run ping 192.168.0.10 and confirm reply.
3. Open LOGO!Soft Comfort → Tools → Parameter VM Mapping → confirm VW0 is mapped to B001 time value. Save and download the program to the LOGO!. The online VM dialog should show the value you assigned in the editor (e.g., 6).
4. Power the KTP Basic. During boot, the panel shows its progress bar, then the start screen. Watch the status bar for connection state.
5. Open a browser on the PC and navigate to the KTP web server (http://192.168.0.20 if the panel is configured for that role, optional). Confirm no S7 connection alarms are pending.
6. On the KTP, open the screen with the I/O field. Read the displayed value and confirm it equals the value currently in VW0 (read by logging into the LOGO! Web editor in parallel).
7. Edit the I/O field on the KTP. Enter a new value (for example, 15) and confirm with Enter. Refresh the Web editor VM view; it must display 15 within one acquisition cycle.
8. Trigger the input that drives B001. The output must energize exactly 15 seconds later.
9. Power-cycle the LOGO! 8 Pure. The newly written VM value must persist if the variable was declared retentive in the VM mapping dialog (default behavior).
10. Power-cycle the KTP Basic. Confirm the S7 connection re-establishes automatically and the displayed value reflects the current VM word.

12. Troubleshooting Matrix and Field-Proven Caveats

Two additional field caveats to internalize:

• The on-delay timer counts only when its trigger input is high. Changing the VM-mapped time while the trigger is low will not change elapsed time until the next rising edge.
• LOGO! 8 FS:03 supports only one PG / OP connection at a time. If both LOGO!Soft Comfort and the KTP are online simultaneously, the panel may lose the connection briefly while the engineering tool polls. FS:04 allows parallel connections and removes this constraint.