Question

I am trying to send a command to my LAC board using visual c++. On page 6 of LAC Config it says that the Buffer is sent in a 3-byte packet.

Buffer[0]=Control

Buffer[1]=Data Low

Buffer[2]=Data High

What does this mean and how do I figure out what I should set each of these values to?

Thanks

Answer 1

If you read on, you will see that next comes a list of all control-codes, followed by a detailed description of each of them. The manual also mentions that sample-code is available, probably somewhere on their website.

In general, setting the values is a bit tricky. BYTE is probably a typedef or macro that resolves to an unsigned 8-bit data-type, meaning it can only hold values from 0 to 255. Two bytes could represent values up to 65535. However, if you want to store a value greater than 255 if that buffer, you’d have to decompose it into its higher and lower byte. You can do this the following way:

unsigned int value = 512;
BYTE low_byte = 0xff & value;
BYTE high_byte = value >> 8;