SEM3 Networking Detail

The following information is detailed networking information for the SEM3 Controller.

Default SEM3 Controller networking settings

SEM3 Controller Ports

SEM3 Controller can handle up to 4 Modbus TCP clients, the onboard webpage when accessed counts as a Modbus client. Meter data is updated/refreshed 15 seconds. When connecting to multiple SEM3 controllers it is recommended to use Google chrome and to clear cache between controllers or to use incognito mode.

Expected TCP traffic and LED indications

• If any TCP traffic is currently active, the TCP/IP LED remains on (Solid Green)
• If all TCP connections are closed, the TCP/IP LED turns off in 2 minutes.
• If for some unforeseen reason, the TCP connections such as Modbus TCP or HTTP related are suspended for 3 minutes, the controller will reboot to correct itself.

SEM3 Controller is intended to be used in a secured network, when external data is needed it is recommended to use a data logging device or to utilize a port forward inside of a secure network to prevent unwelcomed traffic to the SEM3 controller.

Data logging devices in a local network can be used to expose data to an external network. Typically, they are a read only device that allows one-way communications.

A Port forward is a function found in most routers that allows routing traffic with an external IP address and external port to an internal IP address and port. Please refer to your router’s user guide on how to perform a port forward.

For further information see: www.usa.siemens.com/sem3

For further assistance see: http://support.automation.siemens.com/US