GE PACSystems RX7i

Chapter 5. Function Block Diagram (FBD)
GFK-2950C February 2018 247
5.6 Control Functions
The control functions limit program execution and change the way the CPU executes the application
program.
Function
Description
Do I/O Interrupt. For one scan, immediately services a specified range of inputs or
outputs. (All inputs or outputs on a module are serviced if any reference locations on
that module are included in the DO I/O function. Partial I/O module updates are not
performed.) Optionally, a copy of the scanned I/O can be placed in internal memory,
rather than at the real input points.
For details, refer to Control Functions in Chapter 4.
Mask I/O Interrupt. Mask or unmask an interrupt from an I/O board when using I/O
variables. If not using I/O variables, use SVC_REQ 17: Mask/Unmask I/O Interrupt,
described in Chapter 6.
For details, refer to Control Functions in Chapter 4.
Proportional Integral Derivative (PID) Control. Provides
two PID closed-loop control algorithms:
Standard ISA PID algorithm (PID_ISA)
Independent term algorithm (PID_IND)
Note: For details, refer to Chapter 7.
Service Request. Requests a special control system service.
Note: For details, refer to Chapter 6.