Takes too long to send photos

Question

The photos on my ip4 are too large, when sent with text it takes too long, they megas instead of kilos. Can this be adjusted?

Answer 1

Daniel:  I took a look at your code and don't see any problem with it.  However, doing the math:
19,200 BAUD = 19,200 BITS per second.
10 BITS per BYTE ( 1 BIT start + 8 BITS data + 1 BIT stop = 10)
19,200 BAUD = 19,200/10 BITS per BYTE = 1,920 BYTES per second
1,920 BYTES per second / 1000 milliseconds per second = 1.92 BYTES per millisecond (ms)
Now the above would not be a problem since you are only waiting for one character (which should only take 0.52 ms), however, you are sending 5 bytes.  That's a total of 6 bytes round trip or 6 * 0.52 ms = 3.12 ms.
In addition, having "Enable Terminating Char" on your VISA Configure Serial Port can't be helping unless your serial LIN device requires it because having to wait for a teminating character on a read or write (in your case it appears you are using a 0x0A or line feed) increases the number of characters that need to be transmitted. 
Another thought just came to me:  If your serial device is sending a terminating character, it is possible you may have a second read operation each cycle due to the 0x0A (line feed) and the fact that your code only reads one byte at a time from the serial port.  This may also add some time to your response.
I hope this helps.
Message Edited by Bill_in_Detroit on 03-18-2010 09:16 AM