Could someone please explain this?

[Michael]

Hi,

I'm writing a program that interfaces with a device on the serial port and
in the documentation it says the folowing:
3.1.1. Header:Code.



The Header:Code combination is configured thus:



Header: 7 6 5 4 3 2 1 0

< Number of Dims> 1 F/A E/S



Where:



Number of Dims is a value between 0 and 22 identifying the number of dims to
be transmitted (22 is equivalent to 100%)



Bit 2 is always set to '1' to ensure that the interface is able to maintain
synchronization.



F/A defines whether the following byte is a function (1) or address (0).



E/S defines whether the following byte is an extended transmission (1) or a
standard transmission (0).







Could someone please explain what "Number of Dims is a value between 0 and
22 identifying the number of dims to be transmitted (22 is equivalent to
100%)" means?

A link to the documentation:
http://www.marmitek.com/en/software/PROTOCOL.DOC (Bottom of page 2)

Thanks,

Michael

 

[vic]

Hi,

I'm writing a program that interfaces with a device on the serial port and
in the documentation it says the folowing:
3.1.1. Header:Code.



The Header:Code combination is configured thus:



Header: 7 6 5 4 3 2 1 0

< Number of Dims> 1 F/A E/S



Where:



Number of Dims is a value between 0 and 22 identifying the number of dims to
be transmitted (22 is equivalent to 100%)



Bit 2 is always set to '1' to ensure that the interface is able to maintain
synchronization.



F/A defines whether the following byte is a function (1) or address (0).



E/S defines whether the following byte is an extended transmission (1) or a
standard transmission (0).







Could someone please explain what "Number of Dims is a value between 0 and
22 identifying the number of dims to be transmitted (22 is equivalent to
100%)" means?

A link to the documentation:
http://www.marmitek.com/en/software/PROTOCOL.DOC (Bottom of page 2)

Thanks,

Michael

It means bits 7 through 4 form a 5-bit number to be interpreted as the
"dim" value. The value would be : (header & 0xF8) >> 3

There is probably some kind of linear interpolation where 22 means 100%
and 11 50%.

vic

 

[Michael]

It means bits 7 through 4 form a 5-bit number to be interpreted as the
"dim" value. The value would be : (header & 0xF8) >> 3

There is probably some kind of linear interpolation where 22 means 100%
and 11 50%.

vic

Thanks Vic