Configuring Weintek HMI Communication with Siemens LOGO! 0BA8

Overview

Integrating a Weintek HMI with a Siemens LOGO! 0BA8 logic module provides a low-cost visualization layer for small automation cells, building automation, and OEM machine panels. The LOGO! 0BA8 hardware (part of the LOGO! 8 family, OBA7/OBA8 generation) features an integrated 10/100 Mbit Ethernet port that exposes both the S7 communication protocol and the LOGO! native protocol, allowing direct tag polling from EasyBuilder Pro projects.

This reference covers the complete commissioning path: Ethernet topology, LOGO! 0BA8 IP addressing, LOGO! Soft Comfort network configuration, EasyBuilder Pro driver selection, I/Q/M/AI/AQ variable mapping, project download, and the most common field failures (HMI cannot discover points, LOGO! not responding to PC, IP/subnet mismatch). The procedure is written for the LOGO! 0BA8 firmware 1.08.x and EasyBuilder Pro V6.05.x or newer, both current at the time of writing.

System Architecture and Supported Hardware

The 0BA8 base module (0BA8 Standard / 0BA8 Pure) ships with one RJ45 Ethernet port. The 0BA8.S variant adds a second port. For multi-device panels, the second port can be used to daisy-chain the HMI, eliminating the need for an external switch.

Network Prerequisites

Before opening any configuration tool, confirm the following physical and logical conditions. Roughly 80% of the "HMI not discovering points" reports trace to one of the items below.

1. Same subnet: Both the LOGO! and the Weintek HMI must occupy the same IP subnet. The HMI is set in EasyBuilder Pro under System Parameters → IP Address; the LOGO! is set in LOGO! Soft Comfort or directly on the device display.
2. Unique IP addresses: No two nodes may share an IP. Default LOGO! IP is 192.168.0.10; default Weintek HMI IP is often 192.168.0.1 or 192.168.1.1 depending on model. Document both.
3. Subnet mask must be identical (255.255.255.0 is the de-facto standard for small panels).
4. Cabling: For a direct PC-to-LOGO! link, use a crossover or use the HMI as the bridging node. For HMI + LOGO! + PC on a small switch, use straight-through Cat5e.
5. No router/ACL in path during commissioning; the HMI and LOGO! should be on the same Layer-2 broadcast domain.
6. LOGO! display protection must not block Ethernet access. The onboard display has no IP lockout, but verify LOGO! → Settings → Ethernet shows an active link LED on the RJ45.

Step 1: Configure LOGO! 0BA8 Ethernet Parameters

Open LOGO! Soft Comfort V8.x and load the active project. Navigate to Tools → Ethernet Connections (or in older revisions, PC → LOGO! → Ethernet) and enter the IP configuration:

From the LOGO! onboard display: ESC → Settings → Network → IP Address → use the cursor/OK keys to set each octet, then confirm. The display will show 192.168.000.010 when saved. The 0BA8 does not require a restart for IP changes to take effect, but the existing S7/Modbus sockets are torn down for 2-3 seconds.

Step 2: Build or Verify the LOGO! Program and Variable Map

The LOGO! 0BA8 exposes the following addressable areas to Ethernet clients. Weintek's "Siemens LOGO Ethernet" driver in EasyBuilder Pro maps these directly.

To make I/O visible from the HMI, the address must physically exist on the base module or expansion. In LOGO! Soft Comfort, drag an Input I1 contact and a Output Q1 coil to confirm the slot. For a memory flag, use the Special Markers or place a flag block from the toolbox. Tags that have no logic reference will read as 0 in the HMI but will not generate a communication error.

Step 3: Configure EasyBuilder Pro Project

Launch EasyBuilder Pro and create a new project for the target HMI model (e.g., cMT3072X, eMT3105P, iE050).

1. System parameters: Open Home → System Parameters → Device. Set the HMI's own IP address, subnet mask, and gateway. Use a value in the same subnet as the LOGO!, e.g. 192.168.0.20 / 255.255.255.0.
2. Add the LOGO! device: In the project tree, right-click Device/PLC → Add Device. Search for "Siemens LOGO! Ethernet" or "Siemens S7-200 Smart (Ethernet)" depending on the EasyBuilder Pro version; both speak the same S7/ISO-on-TCP protocol. The driver name in current EBPro builds is Siemens LOGO! (Ethernet).
3. Device IP and port: Set the destination IP to the LOGO! address (192.168.0.10). Port defaults to 102 for S7/ISO-on-TCP. The default Weintek slot is 1; slot 0 is reserved on LOGO! for Soft Comfort.
4. Polling interval: Leave the default 1000 ms for a 5" panel; 200-300 ms for a 10"+ panel with dense data. Excessively fast polling (<50 ms) can starve the LOGO! and stall Soft Comfort downloads.
5. Tag database: Open the address book (Address View or Library → Tags) and create the tags. The format is PlcName.Address. Examples:
   • LOGO! 1.I0 — Digital input 1 (Boolean)
   • LOGO! 1.Q0 — Digital output 1 (Boolean)
   • LOGO! 1.M0 — Memory marker M1 (Boolean)
   • LOGO! 1.VW0 — Variable word 0 (16-bit signed, range -32768 to 32767)
   • LOGO! 1.AQW0 — Analog output 1 (16-bit)
6. Add objects to the screen: Drop a Bit Lamp bound to I0, a Bit Switch bound to M0, and a Numeric Display bound to VW0 (set format to 16-bit Signed).

Step 4: Compile, Simulate, and Download

1. Offline simulation: Press F5 (Online Simulation) in EasyBuilder Pro. If the tags read -- or PLC No Response, the HMI cannot reach the LOGO!. Re-check IP/subnet and cabling before continuing.
2. Compile: Use Project → Compile and select Download to HMI. Enter the HMI's IP (192.168.0.20) and project password if set.
3. LOGO! in RUN mode: The LOGO! must be in RUN or STOP — the HMI can read both states. If the LOGO! is in a programming dialog via Soft Comfort, the HMI can still read, but writes are blocked by the LOGO! firmware.
4. Verify on the HMI: The bit lamp should mirror the physical input, the switch should toggle the M marker (which can be wired in the LOGO! program to a real output or a network output).

Step 5: LOGO! Soft Comfort Multi-Connection Setting

When both EasyBuilder Pro and LOGO! Soft Comfort are online simultaneously against the same LOGO! base, the firmware enforces a per-slot connection table. Confirm in LOGO! Soft Comfort:

1. Open Tools → Options → Ethernet and verify the PC IP is in the same subnet.
2. Open PC → LOGO! → Connect. Once connected, go to PC → LOGO! → Connect to S7 to inspect the active S7 partner list.
3. The HMI appears in slot 1. Soft Comfort uses slot 0. If a third-party tool (e.g., OPC UA gateway) holds another slot, the LOGO! will reject the Weintek driver with Connection refused.
4. Disconnect the Soft Comfort online session before heavy HMI debugging to free bandwidth; Soft Comfort keep-alives are 30 s, which can be enough to crowd the bus on 0BA8 base modules with maximum expansion.

IO Mapping Example: Digital Input I1 to a Bit Lamp

The minimal end-to-end check that proves all layers are healthy is: toggle a physical input → HMI bit lamp changes state within 1-2 s. Walk through this example.

1. In LOGO! Soft Comfort, build a one-rung program: I1 contact → Q1 coil. Add an extra M1 contact in parallel for HMI visibility, or use the network output NQ1.
2. Download the program via Ethernet (use the IP, not the LOGO! discovery beacon). Switch the LOGO! to RUN.
3. Wire a 24 VDC source to the physical I1 terminal. Verify the Q1 LED on the LOGO! lights.
4. In EasyBuilder Pro, open the tag database and add tag I0 (PlcName=LOGO! 1, Address=I0). Set the data type to BOOL.
5. Drag a Bit Lamp object to window 10. In its General tab, set Read address to LOGO! 1.I0. Pick a green color for state=1 and grey for state=0.
6. Compile and download to the HMI. Toggle I1; the lamp must follow within the polling interval.

Troubleshooting Matrix

Advanced: Modbus TCP Alternative

If the Weintek project is on a non-LOGO!-aware driver, switch to Modbus TCP/IP Server in LOGO! Soft Comfort (firmware 0BA8 V1.08+ supports Modbus on its Ethernet port) and use the Weintek Modbus TCP/IP generic driver. Register mapping under the LOGO! Modbus server is identical to the S7 mapping, but each address is given a base register (typically 4xxxx for output coils and 3xxxx for input registers). This is useful when the same HMI must also talk to a Schneider, ABB, or Mitsubishi controller on a multi-vendor line.

Verification Checklist

• ping 192.168.0.10 from the PC returns <1 ms on the same switch.
• EasyBuilder Pro Online Simulation shows live I0 and Q0 values without PLC No Response.
• LOGO! display reports the configured IP in the Network menu.
• LOGO! Soft Comfort → PC → LOGO! → Connect succeeds in parallel with the HMI active.
• Bit lamp, numeric display, and bit switch all respond within one polling cycle.
• Cycle LOGO! power — the HMI re-establishes the connection within 5 s with no manual intervention.
• SF/BF LEDs on the LOGO! are off; the Ethernet port shows solid link and blinking activity.

Safety and Operational Notes

FAQ