Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 107)

Chapter
Data Types 8
8 -7
6-Digit, Signed, Fixed Decimal BCD
This value requires two words of the processor data table. The first word
contains overflow, underflow and sign data and the three most significant
digits of the 6-digit BCD integer. The second word contains the lower
three digits of the value. The value ranges from –999999 to +999999.
If an overflow or underflow condition exists, the appropriate bit is set and
a value of 000000 is reported. Fractional portions of any number used
with this routine are truncated. See CALL 13 (page 12 -8) and CALL 23
(page 12 -14).
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
not used
underflow bit (1 = value is fractional and between +1 & –1
(ie. +.999 to –.999)
sign bit (1 = negative; 0 = positive)
overflow bit (1 = value > +999999)
Upper Half BCD Value
15035
D6 D5 D4
Word 1
–
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
D3 D2 D1
Word 2
Lower Half BCD Value
not used
implied
decimal point