Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 81)

Programming
Chapter 3
3Ć38
W61(W68) Loop Status. This word indicates various alarm conditions
for the corresponding loop and contains sign information for certain status
block words. Bits 17 through 00 of the loop status word are defined
below and summarized in Figure 3.12 for loop 1 word W61 and loop 2
word W68.
Figure 3.10
Loop Time/Diagnostic Word W60
a) Loop time
Selected by W01 B07=0.
XYZ = Loop time in milliseconds
b) Diagnostics
Selected by W01 B07=1
AB, CD = Diagnostic error codes
X Y Z
1 0 0 0
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
B C D A
Upper byte two digit
BCD code indicates
which word in the
dynamic block is in error.
Lower byte two digit
BCD code indicates which
word in the loop 1 or loop
2 block is in error
11113
Figure 3.11
Loop Update Time
100 msec
PID Algorithm Internal Housekeeping
Nominal Loop Update Time 100 msec
0
Read
Input
1
Read
Input
2
Calc
Output
1
Calc
Output
2
Set
Output
1
Set
Output
2
11114