Bandwidth describes the information carrying capacity of a channel. Digital data transmission expresses bandwidth in bits per second (bps) such as kbps (1000 bps), Mbps (1000 kbps), or Gbps (1000 Mbps, a billion bits per second). Analog data transmission expresses bandwidth in Hertz (kHz or MHz).

Network bandwidth is important for OPC communication as it defines “how much” data can pass through the network. It is important to note that effective transmission rates are affected by both the available network bandwidth and the quality of transmission. That is, if the available bandwidth is high, but the quality of data transmission is poor, then a lot of errors will be transferred very quickly. However, this communication will rarely be useful for any industrial applications.

See also: Quality of Service (QoS)