Image transfer resume

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By sakshi , 5 June, 2020
Forums
Gurux DLMS for Java

Hi

I want to know can we resume image transfer after connection failure with dlms for java. I have to sent 2000 block. But after 1000 connection get lost due to ping discontinuity. So i want to connect meter again and image data should be transfer from 10001. Could it be possible?

Thanks

Kurumi

6 years 1 month ago

Hi,

I can say that it depends on the meter, but usually, it's possible. You can try to read attribute #4 image first not transferred block number and start sending blocks from that. Or you can read attribute #3 and send missing blocks. It's a bit-string that tells what blocks meter has received.

BR,
Mikko

sakshi

6 years 1 month ago

Step 3: Transfers ImageBlocks.
int[] imageBlockCount = new int[1];
imageBlockCount[0] = (int) (imgData.length / img.getImageBlockSize());

gxReader.readDataBlock(img.imageBlockTransfer(dlms, imgData, imageBlockCount), reply);
Can you tell me how can we pass block number from where i have to initiate?
Above code always try to send block from 1;

sakshi

6 years 1 month ago

hi

Now i want to know can we set block number in data. Because it always start block number from 0 in image data when resume.

is it needed to call imageTransferInitiate method while resuming.
thanks

Kurumi

6 years 1 month ago

Hi,

Because there might be several missing blocks there is no method for this.
You can do it like this:
List<byte[]> packets = new List<byte[]>();
GXDLMSImageTransfer img = new GXDLMSImageTransfer();
byte[][] blocks = img.GetImageBlocks(image);
//Remove blocks that meter has received.
....

//Generate messages.
foreach (byte[] it in blocks)
{
packets.AddRange(client.Method(img, 2, it, DataType.Array));
}
//Send data.

BR,
Mikko