Bandwidth estimation for store-and-forward data

If there is a network disconnection, HCAL sends data to local storage and later forwards the data to the Historian. After the forwarding process starts, HCAL will try to send as much as data as possible with a large packet. The forwarding bandwidth is the bandwidth required to stream the store-and-forward data.

The store-and-forward storage size is the same as for local Historian storage. The following table lists the average sizes used for bandwidth estimation used in this example.

The forwarding bandwidths are calculated using the following formulas:

BandwidthForwarding = 1.04 * 8 * SEach Tag Type (Data Rate * Storage Item Size)

BandwidthRecommendedForwarding = 1.3 * BandwidthForwarding

For this example, if all are stored in the local storage engine and forwarded later, the number of bytes required for every second is as follows:

1. 798 * 8 = 6384 Bytes

2. 815 * 5 = 4075 Bytes

3. 187 * 25 = 4675 Bytes

4. 800 * 37 / 60 = 493 Bytes

5. 800 * 37 / 3600 = 8 Bytes

6. 800 * 280 / 60 = 3733 Bytes

7. 800 * 280 / 3600 = 62 Bytes

BandwidthForwarding = 1.04 * 8 * (6384 + 4075 + 4675 + 493 + 8 + 3733 + 62) = 162 Kbps

BandwidthRecommendedForwarding = 1.3 * 162 Kbps = 211 Kbps