Connecting KTP HMI to LOGO! 8 (0BA8) via Ethernet — Setup Guide

Siemens LOGO! 8 (order suffix 0BA8) Base Modules ship with a built-in 10/100 Mbit Ethernet interface, which makes direct HMI coupling practical without extra communication modules. Any SIMATIC KTP Basic Panel with an Ethernet port — the KTP400 Basic, KTP600 Basic, KTP700 Basic, KTP1000 Basic, and KTP1200 Basic — can be wired to a LOGO! 8 over a standard patch cable. This guide covers the supported panels, the Siemens cable part numbers, the IP addressing scheme, the TIA Portal / LOGO! Soft Comfort configuration, and field verification of the connection.

1. System Architecture

A typical LOGO! 8 + KTP point-to-point architecture looks like this:

For the canonical light-control example from Siemens that exercises exactly this topology, see the Light control with LOGO! and HMI Panel application document (PDF, application ID 109747758).

2. Supported KTP Panels

The following SIMATIC HMI Basic Panels are confirmed for direct Ethernet communication with LOGO! 0BA8. The "Basic" line is the cost-effective range; "Comfort" panels are also supported but only required when features beyond LOGO! tag mapping are needed.

All panels support the SIMATIC S7/LOGO communication driver, which is the only driver required for LOGO! 8 tag access. No additional option or add-on is required on the HMI side.

3. Cables, Connectors, and Siemens Part Numbers

LOGO! 8 and the KTP Basic Panels both use industrial RJ45. A standard Cat 5e SF/UTP patch cable is sufficient for point-to-point links up to 100 m. The Siemens catalog reference for a 2 m grey IE patch cable is:

• 6XV1850-2GH20 — IE TP Cord RJ45/RJ45, 2 m, Cat 5e, pre-assembled, 1:1 wired (TIA-568B). Suitable for direct LOGO! ↔ KTP and LOGO! ↔ PC links.
• 6XV1850-2GN10 — 10 m version of the same cord.
• 6XV1850-2GN50 — 50 m version.

For PC engineering access (LOGO! Soft Comfort program transfer), two cable options exist:

4. IP Addressing Scheme

LOGO! 0BA8 Base Modules ship with default IP 192.168.0.10 and subnet mask 255.255.255.0. The HMI and PC must share the same subnet. A robust small-network default is:

To change the LOGO! IP from the device itself, navigate LOGO! menu → Network → IP Address. To change the KTP IP, use Control Panel → Network and Dial-up Connections → Onboard Ethernet → Properties → IP Address on the panel itself, or push it from the TIA Portal project at transfer time.

5. Configuring the LOGO! 8 Network Parameters

1. Power up the LOGO! 0BA8 Base Module and wait for the display to settle.
2. From the LOGO! onboard display, press ESC to reach the main menu, then navigate to Network.
3. Set the IP Address (default 192.168.0.10), Subnet Mask (255.255.255.0), and confirm that the Server role is enabled (LOGO! 8 is always a server on S7/LOGO).
4. Verify the Ethernet link by plugging the RJ45 patch and observing the LINK LED on the RJ45 socket (solid green = link up).

For an Ethernet ↔ LOGO! programming session from LOGO! Soft Comfort, choose Tools → Select Interface → Ethernet in the Soft Comfort toolbar, then enter the LOGO! IP. The discovery tool (Tools → Discover) will list every LOGO! on the broadcast domain.

6. Configuring the KTP in TIA Portal

Use TIA Portal V17 or later (V18 SP1 is the current mainstream release at the time of writing). The KTP project must use the SIMATIC S7/LOGO protocol driver.

6.1 Add the Panel

1. Open your project, then in the project tree select Add new device → SIMATIC HMI → Basic Panel → [4/6/7/10/12 inch] → KTPxxx Basic.
2. Open the panel's Device Configuration, double-click the PROFINET interface, and enter:
   • IP address: 192.168.0.20
   • Subnet mask: 255.255.255.0

6.2 Create the LOGO! Connection

1. In the project tree, expand the panel → Connections → double-click Connections to open the editor.
2. Click Add and choose the SIMATIC S7/LOGO driver.
3. Set the partner (LOGO!) endpoint:
   • PLC type: LOGO!
   • Address: 192.168.0.10
   • Rack/Slot: 0 / 0 (LOGO! 8 uses Rack 0, Slot 0; do not configure rack 0/slot 1, which is the older S7-200 convention)

6.3 Map Tags

LOGO! exposes the following addressable memory areas to the S7/LOGO driver:

6.4 Compile and Transfer

1. Compile the HMI project (Project → Compile → Software (rebuild all)).
2. Connect the engineering PC to the same Ethernet subnet (192.168.0.x) as the panel.
3. Right-click the panel → Transfer to device → select the panel's IP. The runtime image and project are pushed to the HMI.
4. After the transfer, the panel will auto-start runtime and attempt to connect to the LOGO! IP defined in the connection.

7. Sample Screens (Minimum Viable Project)

For a 3-screen start-up project:

1. Screen 1 — Overview: eight I/O indicator fields linked to DB1.DBX0.0 through DB1.DBX0.7; eight output fields on DB1.DBX8.0–DB1.DBX8.7. Two area-button objects to navigate forward.
2. Screen 2 — Setpoints: two I/O field objects (data type INT) bound to DB1.DBW100 and DB1.DBW102 for entering thresholds into LOGO! variable memory.
3. Screen 3 — Diagnostics: a status display reporting the S7/LOGO connection state (use the system tag Connection state in the HMI tag properties).

Set the start screen in HMI tags → Screen management properties → Start screen = Screen 1.

8. Verification

1. Link layer: the green LINK LED on both the LOGO! RJ45 and the KTP RJ45 must be solid. If only one is lit, the cable or one of the ports is bad.
2. LOGO! ping: from the engineering PC, open a command prompt and run ping 192.168.0.10. Four replies with sub-millisecond time confirm the Ethernet path.
3. HMI runtime connection: on the KTP, open Control Panel → Service / Commissioning → Status / Control. The S7/LOGO connection should report Connected within ~5 s of the panel booting.
4. Tag round-trip: in LOGO! Soft Comfort, force a merker (M1) high. Within one HMI scan cycle (default 1 s), the M1 indicator on the panel must turn on. Force low; it must turn off.
5. Write path: from the panel I/O field on Screen 2, write the integer 1234 into the configured DB1.DBW100 word. In Soft Comfort, place a watch on VW100; the value 1234 must appear.
6. Disconnect behavior: unplug the patch cable. After the configured timeout (default ~5 s), the panel should display a system event "Connection to PLC interrupted". Plug it back in; the connection must auto-recover without restarting the HMI runtime.

9. Troubleshooting Matrix

10. Starter Kits and Alternatives

Siemens bundles several starter kits that include a LOGO! 8 Base Module, a KTP Basic panel, and LOGO! Soft Comfort on a single DVD or download card. Check the Siemens LOGO! product page for the current regional part numbers (e.g., 6ED1057-3BA01-0AA8 in EU). These kits remove the cable-compatibility guesswork and pre-validate the panel firmware against the LOGO! 0BA8 firmware shipped in the kit.

If you have a non-Basic Comfort Panel (TP700 Comfort, TP1200 Comfort), the same S7/LOGO driver and addresses apply, but you also gain access to PROFIenergy, Sm@rtServer, and Web features on the HMI side. Stick with Basic Panels for cost-sensitive LOGO! deployments where only tag visualization is needed.

11. Best Practices

• Document the IP and rack/slot in the panel name in the TIA Portal project tree (e.g., "KTP600_192.168.0.20_R0S0") for faster field replacement.
• Reserve a static range (192.168.0.10–.30) for LOGO! networks and keep DHCP out of the same scope.
• For multi-LOGO! projects (LOGO! ↔ LOGO! + KTP), use a small managed switch and reserve IP-per-MAC entries; unmanaged switches are fine for ≤ 4 devices.
• Set the LOGO! display password if the cabinet is field-accessible — the HMI will still control outputs even if the LOGO! onboard UI is locked.
• Keep the LOGO! 0BA8 firmware on FS08 or later; the DB1 area layout was extended in earlier FS releases and tag offsets differ.
• Always transfer a backup of the compiled HMI runtime + the LOGO! Soft Comfort .lsc program to the project archive.

12. FAQ