Connect CNC milling machine with Siemens PLC - Siemens S7 communication
Our software offers a flexible and powerful interface for TCP server/client and Modbus TCP client communication. This allows you to connect your CNC machine directly to Siemens PLC - easily, reliably and in real time.
Set-up is particularly simple and takes just two steps:
1. define data channels
Using the administration of the data channels (menu: Extras → Data channels), you can define in just a few steps which information should be sent or received. For example, you can automatically transmit the current X-position of the CNC machine or receive external commands such as „Start job“ and execute them immediately (see Fig. 1).

The following commands are currently available:
- Transmit position values of the CNC machine (X, Y, Z, A, B, C)
- Send status code of the CNC machine
- Send file name
- Send G-code line
- Send value of a G-code R parameter
- Start job on receipt of the value
- Stop job on receipt of the value
- Execute reference run on receipt of the value
- Move to zero point on receipt of the value
- Move to parking point on receipt of the value
- Execute macro
- Receive change of a G-Code-R parameter
- Reduce speed in the status bar by 10 %
- Increase speed in the status bar by 10 %
- Send current speed value of the status bar in per cent
2. Siemens S7 communication (JSON-based)
Siemens S7 controllers can be connected directly via S7 communication. Data is exchanged via data blocks and is fully JSON-configurable. Ideal for structured automation solutions. Siemens S7 PLC (S7-200, S7-300, S7-400, S7-1200, S7-1500) are supported.
The function is available from cncGraF version 8.0.108.
Set up Modbus TCP Client
The connection is created in the dialogue „TCP Server/Client and Modbus TCP Client“ and the desired data channel is assigned via filters (see Fig. 2).

Highlights:
- Simple configuration of TCP and Modbus connections
- Direct integration with Siemens PLC and other control systems
- Flexible package definition with customised separators and markers
- Support for Modbus holding registers and coils
Whether machine control, process monitoring or automation: With our solution, you can connect your CNC milling machine securely and conveniently via TCP/IP or Modbus TCP.