Network types

The two basic types of communication networks for PME are Ethernet and serial.

Ethernet (TCP) networks

Ethernet (TCP) device networks can be integrated into regular corporate LANs or they can be separate, independent networks, providing a higher level of security and availability.

Devices are configured in PME by providing fixed IP addresses (IPv4 or IPv6) and ports, or based on host names. Host names must be used for devices with dynamic address assignment, for example using the DHCP protocol. When host names are used in PME, then a host name resolution mechanism is required by the external IT network.

Device communications are based on encapsulated Modbus or ION protocol and are not encrypted. Bandwidth requirements per device are typically low, but depend heavily on the amount and type of data requested from the device by PME.

Ethernet (TCP) networks are in many ways superior to serial networks and we recommend that you use Ethernet (TCP) networks whenever possible.

Serial device networks

Serial communication is the traditional way of connecting devices to PME. Serial communications require an intermediate converter or gateway, for example a Link150, to establish a network connection. The performance of a serial communication network can become the limiting factor for the overall system performance.

NOTE: If you use an ION meter as a gateway, with Ethergate protocol, you lose the ability to multi-master the serial devices.

Serial device communications are based on Modbus RTU or ION protocol and are not encrypted. See Tools for information on how to design a serial network.

PME also supports communication through telephone modems.

Reasons for using serial networks include:

The device type only supports serial communications.
A serial communication network is already in place.
The existing Ethernet (TCP) networks do not allow the connection of monitoring devices.
Serial communications are less affected by electrical noise.

Ethernet (TCP) networks are in many ways superior to serial networks and we recommend that you use Ethernet (TCP) networks whenever possible.