Rockwell Automation GMLC Reference Manual - Manual (Page 412)

Publication GMLC-5.2 - November 1999
Auto RIO Update 375
The most significant bit is at:
PLC I:046/17 (RIO output 83)
The sign bit is:
PLC I:047/17 (RIO output 99)
It is 0 for a positive value and 1 for a negative value.
PLC inputs I:047/14 through I:047/16 (RIO outputs 96 – 98)
contain a value between 0 and 7 indicating the number of decimal digits
(digits to the right of the decimal point) in the formatted data output group
magnitude in I/O Group 6. The motion controller automatically
determines this value to maintain the maximum number of significant
digits in the displayed value. This value typically changes from update to
update. Thus, if the current position of Axis 0 is –123.45, the PLC input
image table for rack 4 is updated as shown below (x = don’t care):
Value is negative I:047/17 = 1
2 Decimal digits 2
10
= 010
2
⇒
I:047/16, …/15,…/14
Magnitude 123.45 x 10
2
= 12,345 = 3039
16
= 011 0000 0011 1001
2
I/O
Group
15 (SLC)
17 (PLC)
08
10 07
07 00
00
0 x x x x x x x x x x x x x x x x
1 x x x x x x x x x x x x x x x x
2 x x x x x x x x x x x x x x x x
3 x x x x x x x x x x x x x x x x
4 x X x x x x x x x x x x x x x x
5 x X x x x x x x x x x x x x x x
6 0 0 1 1 0 0 0 0 0 0 1 1 1 0 0 1
7 1 0 1 0 x x x x x x x x x x x x