Siemens SIMOTION Remote Connection with SMX-RNS20

Overview

Siemens SIMOTION controllers (D, C, and P platforms) use the PROFINET/Industrial Ethernet protocol for programming via SCOUT or TIA Portal. This guide shows how to configure an SMX-RNS20 so that SCOUT can reach the SIMOTION controller remotely.

The recommended connection and settings are illustrated in the screenshots below:

Step 1 — SIMOTION / SMX-RNS20 connection settings

Step 2 — SIMOTION / SMX-RNS20 connection settings

Machine-Side Setup (SMX-RNS20)

1. Connect the SMX-RNS20’s LAN port to the same network switch as the SIMOTION controller.
2. Log in to the SMX-RNS20 web interface (192.168.1.1 default) and verify the device is online and registered.
3. Under Network → LAN, note the subnet used. The SIMOTION controller’s IP must be in the same subnet as the SMX-RNS20 LAN interface.
4. No additional port-forwarding rules are required — the SMX tunnel bridges the entire LAN subnet.

Engineering PC Setup (SX-Client)

1. Open SX-Client and connect to the SMX-RNS20 device.
2. Wait for the tunnel status to show Connected. A virtual network adapter will appear on your PC with an IP in the remote machine’s subnet.
3. Open Siemens SIMOTION SCOUT or TIA Portal.
4. In SCOUT, go to Set PG/PC Interface and select TCP/IP → [your PC’s virtual adapter].
5. Perform an “Accessible Nodes” scan — the SIMOTION controller should appear.
6. Connect to the controller and proceed with programming or diagnostics as normal.

Note

SIMOTION SCOUT uses PROFINET discovery (DCP broadcast). Because the SMX tunnel operates at Layer 3 (IP), DCP broadcasts are not forwarded by default. Use direct IP address to connect in SCOUT instead of relying on automatic device discovery.