Allen-Bradley SLC 500 Series

Publication 1747-RM001G-EN-P - November 2008
9-14 Proportional Integral Derivative Instruction
PID Rational Approximation Bit (RA)
When the RA bit is set, rational approximation method is used for PID
computation, resulting in a more accurate output.
PID Enable (EN)
The PID enabled bit is set (1) whenever the PID instruction is enabled. It
follows the rung state.
Integral Sum
This is the result of the integration .
Table 9.22 PID Rational Approximation Parameter
Tuning Parameter
Descriptions
Address Data Format Range Type User Program
Access
RA - Rational
Approximation
Word 0,
Bit 14
binary (bit) 0 or 1 control read/write
Table 9.23 PID Enable Parameter
Tuning Parameter
Descriptions
Address Data Format Range Type User Program
Access
EN - PID Enable Word 0,
Bit 15
binary (bit) 0 or 1 status read only
Table 9.24 Integral Sum Parameter
Tuning
Parameter
Descriptions
Address Data Format Range Type User Program
Access
Integral Sum Word 17
and 18
long word
(32-bit INT)
-2,147,483,648 to
2,147,483,647
status read/write
1
T
I
-
----
Etd()
∫