GE Multilin W650 - B.4.3 Snap-Shot Events

B-12 W650 Wind Generator Protection System GEK-113032A
B.4 MODBUS APPENDIX APPENDIX B
B
B.4.3 SNAP-SHOT EVENTS
Nowadays, event retrieval is completely compatible with UR family. In the W650, the NEW EVENTS concept has been
extended, providing additional functionality. These are the events created after the last request.
Firmware version 1.60 adds a new way of reading snapshot events in binary format. Before this version, the relay sent
information in ASCII format. The snapshot event retrieval is similar to the ASCII.
a) SNAPSHOT EVENT READING IN ASCII FORMAT
The events capture process is based on the opening and reading of a pseudo-file. This process is made in two steps:
1º.- A writing message in the ‘0xfe00’ address, where desired opening file name is written:
- “EVE .TXT”: to obtain all
- “NEW_EVE.TXT": to obtain events created from the last request of this same file
- “EVE0234 .TXT “: to obtain events starting, for example, from 234 rating
2º.- The second and following ones are messages of reading on 0xff00 address, where 244-byte strings are read
from the open file. As this process is a request process, if there was a response string with error, the last string can be
requested again, by a reading message on 0xff02 address.
The first reading message shows the events format, information is transmitted in the rest of messages. In the same string,
the first four bytes indicate the file reading position and the following two bytes form a short with the quantity of useful bytes
sent (if it is lower than 244, this indicates that it is the last message).
In the second step, many BUSY responds may be produced, because internally the ASCII format file is being created.
b) SNAPSHOT EVENTS READING IN BINARY FORMAT:
Write a message in address 0xfe00 to open the file.
“EVE.BIN”: to read all Snapshot events.
“NEW_EVE.BIN”: to read new events since the last reading of this file.
“EVE0234.BIN”: to read events starting by number 234.
The second and successive messages are read in address 0xff00 in blocks of 250 bytes (4 bytes that indicate the point
value to the file, 2 bytes that indicate the number of data sent, and 244 data bytes). If during this process there is an error
response, the request can be repeated in address 0xff02 reading 246 bytes (2 bytes that indicate the number of bytes sent,
and 244 data bytes).
Each Snapshot event includes:
1º byte: event format code.
N bytes: Event information structured depending on the code
At this moment there is only one format type with code 0. Its structure is as follows:
• -UINT16: event handle.
• -8 bytes: event date and time.
• -29 bytes: event cause. (string finished in null).
• -UINT32: Phasor Ia (scaled to 1000).
• -UINT32: Phasor Ib (scaled to 1000).
• -UINT32: Phasor Ic (scaled to 1000).
• -UINT32: Line Frequency (scaled to 1000).
• -UINT32: Phasor Ig (scaled to 1000).
• -UINT32: Phasor Isg (scaled to 1000).