Description

The Delta HMI to Siemens S7-200 PLC communication cable (Model: S7200-DOP) is designed to establish a serial data link between Delta’s DOP-series Human Machine Interfaces (HMIs) and Siemens’ S7-200 PLCs. This cable enables configuration, monitoring, and control of the Siemens PLC through the Delta HMI. Below are the key details:

Key Features & Compatibility

1. Compatibility:

   • Delta HMI: Compatible with DOP-B series (e.g., DOP-B07S, DOP-B10S) and other DOP models with RS-485/RS-232 ports.

   • Siemens PLC: Works with S7-200 series (e.g., CPU 224, CPU 226) via the PPI/RS-485 port.

2. Interface:

   • HMI Side: Typically uses a 9-pin RS-232 or RS-485 port (depending on the HMI model).

   • PLC Side: Connects to the Siemens S7-200’s 9-pin D-Sub RS-485 port (PPI port).

   • Cable Type: Acts as a protocol converter or physical adapter to bridge Siemens PPI/Modbus and Delta HMI communication protocols.

3. Communication Protocol:

   • Configure the Delta HMI to use Modbus RTU (Siemens S7-200 supports Modbus via its自由口通信 (Freeport) or libraries like Modbus Slave).

   • Ensure matching baud rate, parity, and data bits on both devices.

Wiring Configuration

The cable connects the RS-485 pins of the Siemens PLC to the RS-485/RS-232 pins of the Delta HMI. Below is a typical RS-485 2-wire setup:

Notes:

• For RS-232 connections on the HMI side, use an RS-232 to RS-485 converter.

• Add a 120Ω termination resistor across A/B lines if the cable is long (>50m).

• Shield the cable and ground the shield at one end to reduce noise.

Software Configuration

1. Delta HMI (DOPSoft/DOPSoft Pro):

   • Select Modbus RTU as the communication protocol.

   • Set parameters:

     • Baud Rate: 9600, 19200, etc. (match PLC settings).

     • Data Bits: 8.

     • Parity: Even/Odd/None (must match PLC).

     • Station Address: PLC Modbus address (e.g., 1).

   • Map HMI elements (buttons, displays) to Siemens PLC registers (e.g., V, M, Q addresses).

2. Siemens S7-200 PLC:

   • Use STEP 7-Micro/WIN to configure the PLC’s communication port:

     • Set Port 0/1 to Freeport Mode with Modbus RTU parameters.

     • Load a Modbus Slave Library (if required) to enable Modbus communication.

   • Ensure PLC register addresses align with HMI addressing (e.g., V-registers in Siemens map to 4xxxxx addresses in Modbus).

Typical Applications

• Real-time monitoring of PLC data (e.g., temperature, pressure).

• Control of PLC outputs (e.g., motors, valves) via HMI touchscreen.

• Alarm management and historical data logging.

Troubleshooting Tips

• No Communication:

  • Verify wiring polarity (swap A/B if needed).

  • Check for matching baud rates and parity settings.

  • Ensure the PLC’s Modbus library is correctly initialized.

• Intermittent Data:

  • Add termination resistors and check cable shielding.

  • Reduce cable length or use repeaters for long distances.

• Address Mismatch:

  • Confirm Modbus address mapping (e.g., Siemens V100 maps to Modbus 40101).

Alternatives

• Ethernet Communication:

  • Use a Siemens CP243-1 (Ethernet module) for S7-200 and configure the Delta HMI for Modbus TCP.

• Protocol Converters:

  • Deploy a standalone Modbus RTU to PPI converter for seamless integration.

Required Components

1. Delta HMI Software: DOPSoft or DOPSoft Pro.

2. Siemens PLC Software: STEP 7-Micro/WIN (for PLC configuration).

3. Cable: Custom S7200-DOP cable or DIY wiring as per pinout above.