PowerLogic T500 - Maximum capacity of buffer events in case of Scada connection loss

[DhananjayJamdade]

Hello All,

I understand that HU280 CPU hold the protocol buffer events in case of SCADA connection failure initially and thereafter power loss/reboot.

However, I would like to know maximum number of events stored in buffer memory per open standard telemetry protocol such as: IEC 61850, IEC 101, IEC 104 and DNP3.

[JuanRayo]

Hello @DhananjayJamdade 

For IEC 61850

Each buffered RCB instance has two circular buffers of 20 kB:

• one for GI reports
• one for event triggered reports.

Beware: configurable buffer size is not supported.

How many events can be buffered in 20kB?

• It depends on the Information Report Option Fields and the Common Data Class in question.
• The 61850 Brick is quite efficient in only storing the absolutely necessary data in the buffer.

To calculate how many events this equates to, we need to consider specific DO types. For example, one SPS DO event in a typical status dataset of 64 SPS DOs. Each entry in the RCB buffer stores:

• The EntryID = 8 bytes
• The TimeOfEntry = 10 bytes
• The Inclusion Bitstring = 8 bytes
• The Data Value, stVal + q + t, 1 + 2 + 12 = 15 bytes
• The Reason-for-inclusion = 1 byte
  Total: 42 bytes

Therefore a server side BRCB buffer could store approximately 20kB / 42 = 487 such SPS events

For DNP3.0 slave

Buffer size could be configured in Easergy Builder for every Object type like here below:

• 150 is the default value but can be configured up to 65535 events.

For IEC 101-104 slave

Buffer size could be configured in Easergy Builder for every point type like here below:

• In the above picture, you got default values but that may be configured to up to 65535 events.

[DhananjayJamdade]

Thank you