Contents
GFK-0467K Contents xv
PID Parameter Block:.....................................................................................4-173
Operation of the PID Instruction.....................................................................4-175
Internal Parameters in RefArray......................................................................4-178
PID Algorithm Selection (PIDISA or PIDIND) and Gains.............................4-179
CV Amplitude and Rate Limits.......................................................................4-180
Sample Period and PID Block Scheduling......................................................4-181
Determining the Process Characteristics.........................................................4-181
Setting User Parameters Including Tuning Loop Gains..................................4-182
Setting Loop Gains — Ziegler and Nichols Tuning Approach.......................4-183
Sample PID Call.............................................................................................4-184
Appendix A Instruction Timing............................................................................................. A-1
Boolean Execution Speed....................................................................................... A-10
Appendix B Interpreting Fault Tables...................................................................................B-1
PLC Fault Table............................................................................................................... B-2
I/O Fault Table................................................................................................................. B-8
Appendix C Instruction Mnemonics...................................................................................... C-1
Appendix D Key Functions..................................................................................................... D-1
Appendix E Using Floating-Point Numbers...........................................................................E-1
Floating-Point Numbers ............................................................................................E-1
Internal Format of Floating-Point Numbers.............................................................. E-3
Values of Floating-Point Numbers............................................................................ E-4
Entering and Displaying Floating-Point Numbers.................................................... E-5
Errors in Floating-Point Numbers and Operations.................................................... E-6