Contents
viii PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
6.32 SVC_REQ 56: Logic Driven Read of Nonvolatile Storage .............................................. 331
6.32.1 Discrete Memory .................................................................................................................................................... 331
6.32.2 Storage Disabled Conditions ............................................................................................................................. 331
6.32.3 Maximum of One Active Instruction .............................................................................................................. 331
6.32.4 ENO and Power Flow To The Right ................................................................................................................. 331
6.32.5 Parameter Block ..................................................................................................................................................... 332
6.33 SVC_REQ 57: Logic Driven Write to Nonvolatile Storage ............................................ 335
6.33.1 Length of Data Written ........................................................................................................................................ 335
6.33.2 Write Frequency ..................................................................................................................................................... 335
6.33.3 Erase Cycles ............................................................................................................................................................. 336
6.33.4 Discrete Memory .................................................................................................................................................... 336
6.33.5 Retentiveness .......................................................................................................................................................... 336
6.33.6 Maximum of One Active Instruction .............................................................................................................. 336
6.33.7 Storage Disabled Conditions ............................................................................................................................. 336
6.33.8 Error Checking ......................................................................................................................................................... 336
6.33.9 Fragmentation ........................................................................................................................................................ 337
6.33.10 When nonvolatile storage is full .................................................................................................................... 337
6.33.11 Equality .................................................................................................................................................................... 338
6.33.12 Redundancy ........................................................................................................................................................... 338
6.33.13 ENO and Power Flow to the Right ................................................................................................................ 338
6.33.14 Parameter Block for SVC_REQ 57 ................................................................................................................. 339
Chapter 7 PID Built-In Function Block .................................................................................................... 343
7.1 Operands of the PID Function ............................................................................................ 344
7.1.1 Operands for LD Version of PID Function Block ........................................................................................ 344
7.1.2 Operands for FBD Version of PID Function Block ..................................................................................... 345
7.2 Reference Array for the PID Function .............................................................................. 346
7.2.1 Scaling Input and Outputs .................................................................................................................................. 346
7.2.2 Reference Array Parameters ............................................................................................................................. 347
7.3 Operation of the PID Function ........................................................................................... 353
7.3.1 Automatic Operation ........................................................................................................................................... 353
7.3.2 Manual Operation .................................................................................................................................................. 353
7.3.3 Time Interval for the PID Function .................................................................................................................. 354
7.4 PID Algorithm Selection (PIDISA or PIDIND) and Gain Calculations ........................ 355
7.4.1 Derivative Term ...................................................................................................................................................... 356
7.4.2 Error Term Mode .................................................................................................................................................... 356
7.4.3 Derivative Action on PV Bit ................................................................................................................................ 356
7.4.4 Combined Operation of Error Term and Derivative Action Modes .................................................... 356
7.4.5 CV Bias Term ............................................................................................................................................................ 357
7.4.6 CV Amplitude and Rate Limits .......................................................................................................................... 357
7.4.7 Sample Period and PID Function Block Scheduling .................................................................................. 358