RSLogix 5000 Structured Text

[rajy2r]

I don't use structured text too much, but wanted to loop some items, so i thought i should try it. Got a hang up.

What i am trying to do is to check FIFO_ALM_RSLT_WORD array individual bits to see which one is set first, and copy some text and time values into a UDT Fifo and exit after first item is found.
How do i address bit level for looping? FIFO_ALM_RSLT_WORD[0].SUBSCRIPT, so i can check all bits. Would appreciate the help.

BMS1_ALM_LOG_NEW.YEAR := PLC_Year;
BMS1_ALM_LOG_NEW.MONTH := PLC_Month;
BMS1_ALM_LOG_NEW.DAY := PLC_Day;
BMS1_ALM_LOG_NEW.HOUR := PLC_Hour;
BMS1_ALM_LOG_NEW.MIN := PLC_Min;
BMS1_ALM_LOG_NEW.SEC := PLC_Second;

SUBSCRIPT0:=0;
SUBSCRIPT1:=0;

FOR SUBSCRIPT0:=0 to 31 by 1 do

IF FIFO_ALM_RSLT_WORD[0].SUBSCRIPT0 then
COP(FIFO_ALM_STRING_ARRAY[SUBSCRIPT0], BMS1_ALM_LOG_NEW.ALM, 1);
RET( );
END_IF;
END_FOR;

FOR SUBSCRIPT1:=0 to 31 by 1 do

IF FIFO_ALM_RSLT_WORD[1].SUBSCRIPT1 then
COP(FIFO_ALM_STRING_ARRAY[SUBSCRIPT1], BMS1_ALM_LOG_NEW.ALM, 1);
RET( );
END_IF;
END_FOR;

RET( );

 

[ttichy]

how about doing a bitwise AND to get to the bit level..
something like:
FOR n:=0 to 31 by 1 do
IF (FIFO_ALM_RSLT_WORD[0] AND 2**n)=1 then
COP(FIFO_ALM_STRING_ARRAY[n], BMS1_ALM_LOG_NEW.ALM, 1);
RET( );
END_IF;
END_FOR;

 

[rajy2r]

how about doing a bitwise AND to get to the bit level..
something like:
FOR n:=0 to 31 by 1 do
IF (FIFO_ALM_RSLT_WORD[0] AND 2**n)=1 then
COP(FIFO_ALM_STRING_ARRAY[n], BMS1_ALM_LOG_NEW.ALM, 1);
RET( );
END_IF;
END_FOR;

That's a good way to do.
I tried FIFO_ALM_RSLT_WORD[0].[SUBSCRIPT0], and there are no compile errors. Would have to test and see if it works. If not, i think the Bitwise & a great approach.