Device serial numbers and unique identifiers

[EcoStruxureIT]

The EcoStruxure IT Gateway must uniquely identify devices to support data analytics and sensor history.

The Gateway attempts to use the device's serial number as the unique identifier whenever possible, since IP addresses change, devices are removed and re-added to a network, or a device is connected to different Gateways. 

In some cases, the device serial number must be set manually.

Device serial number is missing or invalid

In most cases, if the serial number is missing or empty, or it matches a list of invalid values like1234567890 or N/A, the Gateway attempts to use the MAC address for SNMP or the IP Address + server ID + port for Modbus. This not perfect for this situation, but it is the best alternative.

If the Gateway fails to find a unique identifier, the device discover fails and is reported the Gateway's discovery log.

Devices have the same unique identifier

If two devices have the same unique identifier, usually one device will be discovered, and then when the second is discovered, the first will be removed and replaced by the second since it appears to be the same device. In some cases, depending on the timing, both devices could be discovered, and then will lose connectivity when the Gateway is updated to the next version. 

Manually set the serial number on a device

You might need to set the serial number on a device if a unique identifier cannot be not found. Consult the documentation or the device's manufacturer for how to do this if necessary.

If you can update the serial number manually, it's most likely done through the device's own user interface. It might also be possible to set it using SNMP or Modbus. Contact customer support if you need assistance. You may need to supply the SNMP MIB or Modbus map to determine the address of the serial number.