Selection reference · illustrative scenario
Clock roles in the application
PLC processing, fieldbus and event logs may use different references. Separate operating clocks from RTC backup functions for a clearer engineering and procurement review.
Engineering selection review
Review host inputs for processing and communications alongside backup timekeeping, start-up and power interference. Crystal error alone does not determine scan-cycle or synchronization accuracy.
Procurement and documentation
Include cpu / bus controller and operating and rtc roles, plus the existing full code, sample and production quantities and delivery target. Discuss nominated international brands and domestic candidates separately, confirming parameters and documents by part.
Illustrative validation scenario
Compare original and candidate parts with the same application program across restart, power recovery, communications and event-log timing, retaining specification revisions.
Inquiry & validation checklist
- CPU / bus controller
- Operating and RTC roles
- CL/ESR or active signaling
- Power-loss, restart and log validation
