Emerson PNC001-A Series User Manual

PACSystems™ RX3i and RSTi-EP CPU Reference Manual Appendix A
GFK-2222AK October 2019
Serial I/O, SNP & RTU Protocols 199
The following diagram shows the differences between the full sweep phases and the base
sweep phases.
Base Sweep vs. Full Sweep Phases
Base Sweep
Full Sweep
<START OF SWEEP>
Sweep Housekeeping

NULL Input Scan
85

Program Logic Execution

NULL Output Scan
85










<END OF SWEEP>
<START OF SWEEP>
Sweep Housekeeping

Input Scan
85

EGD Consumption Scan
86

Program Logic Execution

Output Scan
85

EGD Production Scans
86

Poll for Missing I/O Modules
87

Controller Communications Window

Backplane Communications Window
<END OF SWEEP>
For the base sweep, if there is no configuration, the input and output scan phases of the
sweep are NULL (i.e., check for configuration and then end). The presence of a
85
If I/O is suspended, the input and output scans are skipped.
86
If no Ethernet Global Data (EGD) exchanges are configured, the consumption and production scans are skipped.
87
Polling for missing I/O modules only occurs if a Loss of ... fault has been logged for an I/O module.

Emerson PNC001-A Series Specifications

General

Brand	Emerson
Model	PNC001-A Series
Category	Controller
Language	English