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

viii

PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual

GFK-2950C

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