Byte conversions

[Rodney]

Hi

please see attached

excuse my ignorance on this topic as a non programmer newbie this is an area I know little about

I need to access the the bytes (I think) of the registers to use the data

I can return the data readinputU16 but don't know what to do with it.....

I have read the manual section 4.12.10 on byte conversions but I'm a little lost

for hex register 3201 (Decimal 12801) if I wanted to access the value in D9 (load over current) (I am assuming it will be either 1 or 0) what is the expression to do this?

similarly D3-D2(charging status) how do I access the value (2 bytes?) - what is the expression for this?

Regards

Rodney

 

 

  

 

[AzeoTech]

For a bit, you can use TestBit().  For a group of bits (say D7-D4 of A15), you would have to mask and shift:  (value >> 4) & 0x07.  This is basic bitwise boolean math that is covered in basic old-school computer science texts if you want to read more.

 

[Rodney]

Hi

Sorry for the late reply but other issues on my project have taken priority..... 

Can you confirm if I have understood you reply

if I named A15 above Batt_Status and I want to return  D8

then the syntax is

TestBit(Batt_Status[0],8)

D7-D4

(Batt_Status[0]>>4) & 0x07

and

D3-D0

(Batt_Status[0]>>4) & 0x03

if I named A16 CES and I wanted the charging status (D3-D2)

(CES[0]>>2) & 0x03 

Thank you 

Rodney

 

 

 

[Rodney]

sorry one final syntax to check

if I wanted A16  D15-D14

would it be

(CES[0]>>2) & 0x0F

thanks

 

 

 

[AzeoTech]

Most no. You have the wrong hex values.  You have to think in binary, and might want to use binary notation instead::

D7-D4

(Batt_Status[0]>>4) & 0b1111

and

D3-D0

Batt_Status[0] & 0b1111

if I named A16 CES and I wanted the charging status (D3-D2)

(CES[0]>>2) & 0b0011 

if I wanted A16  D15-D14

would it be

(CES[0]>>14) & 0b11