Situation
MES dashboards disagreed with PLC totals by up to eight percent on high-speed lines. Finance challenged OEE reporting; operators re-keyed downtime reasons because MES pick lists did not match alarms they saw.
Problems encountered
- Multiple integrators had defined “good count” differently (pulse vs completed cycle).
- Clock skew between servers and PLCs distorted batch timestamps.
- Firewall rules blocked IT from testing during production.
Engineering response
TECHNLOGIX PTY LTD authored an ICD defining count edges, reset conditions, and rejected product handling. NTP alignment was enforced on OT switches participating in the path. Staging VLAN mirrored production tags for two-week shadow mode before write-enabled commands were enabled.
Outcomes
Count variance between PLC and MES narrowed on the lines under review. Downtime reasons were auto-populated for most stops once operators trusted the mapping. IT signed off cyber controls with documented read/write separation.