Siemens SIMATIC 505 - Description; Chapter 4 Discrete Outputs

Software Interface
2-15
2.6.10
Constant 9 contains the velocity loop reset (integral) value. Reset constant
for PID calculation: 0–32767 in PLC = 0–327.67 ms. For example,
20000 = 200 ms reset factor .
NOTE: The larger the reset value ⇒ the smaller the reaction time on the
PID calculation.
2.6.11
Constant 10 contains the velocity/pressure operation bit values. V alues
stored in constant 10 determine velocity and pressure algorithms for PID
calculations. A zero in this word accepts the default selection as follows:
• Standard PID algorithm for both velocity and pressure loop calculation
• No filtering on input
• 0 to +10 V outputs
• No inhibit on pressure transfer
If changes to the default selection are required, the bit assignments for
constant 10 are described below .
Bits 1–2
V elocity Algorithm
V elocity Byte Pressure Byte Description
1 8 9 16
[00.. ....] [.... ....] Select
standard PID algorithm for
velocity (default)
[01.. ....] [.... ....] Select dynamic PID algorithm for
velocity calculation
[10.. ....] [.... ....] Reserved
[11.. ....] [.... ....] Reserved
Bits
3–4
Filters
V
elocity Byte Pressure Byte Description
1 8 9 16
[..00 ....] [.... ....] Select no filter for velocity calculation
(default)
[..01 ....] [.... ....] Select
filter on position for velocity
calculation
[..10 ....] [.... ....] Select
filter on range for velocity
calculation
Constant 9
Constant 10