Acquiring Data through serial port

[Hameed97]

Hi,

I am acquiring data through a serial port. I have to acquire 25 different data packets with different headers. 22 of the packets are 90 bytes each while the remaining 3 are 30 bytes each. For example:

Packet 1: $SM123........89 (header=$SM, total bytes = 90)

Packet 1: $FG123........89 (header=$FG, total bytes = 90)

.

.

Packet n: $XY123........89 (header=$XY, total bytes = 90)

Packet n+1: $YZ123........29 (header=$YZ, total bytes = 30)

I can acquire a data packet with the same header, but can't do with all the headers. 

[GerdW · Accepted solution]

Hi Hameed,

---

@Hameed97 wrote:

I am acquiring data through a serial port. I have to acquire 25 different data packets with different headers. 22 of the packets are 90 bytes each while the remaining 3 are 30 bytes each. 

---

Do those messages come with a (well-defined) TermChar?

Why not use that TermChar and request ALWAYS 100 bytes from VISARead?

When there is no TermChar: read just 3 bytes to receive the header ("$xy"), then read the number of bytes expected for that header…

Do you know this excellent video?

[Hameed97]

Hi,

I have to acquire different data packets with different data lengths and different header Bytes. For example,

packet 1: $HA123....89 (3 header bytes, total length: 90) 

.

.

packet 15: $MN123....29 (3 header bytes, total length: 30)

...

packet 24: $YZ123....49 (3 header bytes, total length: 50) 

How can I do this. 

[GerdW]

Hi Hameed,

instead of high-jacking very old threads you could also answer questions in your own thread!

[Hameed97]

Hi GerdW,

There is no TermChar,

"When there is no TermChar: read just 3 bytes to receive the header ("$xy"), then read the number of bytes expected for that header…"

This simple solution worked very well.

The video you mentioned is also very useful.

Thanks

Best regards,

Hameed

[Hameed97]

HI GerdW,

Yes, you are right, I should have followed my thread instead of following an old thread.

Best regards,

Hameed