What DAHS does (simple)
- Collects analyzer values (analog, digital, Modbus, OPC, etc.)
- Applies scaling, conversion, and reporting basis rules
- Applies validity flags (calibration, faults, warm-up)
- Stores data and generates compliance reports
Field tip: A perfect analyzer can still produce bad reports if DAHS mapping/scaling is wrong.
Common DAHS issues
Wrong Scaling
ppm looks 10× high/low, wrong units, wrong range mapping.
Bad Time Sync
Data gaps, misaligned events, calibration periods recorded incorrectly.
Flags Not Applied
Invalid data reported as valid during calibration or fault states.
Communication Instability
Network drops, IP changes, device restarts, bad cables/switch ports.
DAHS verification checklist (technician)
- Confirm tag mapping (each analyzer channel to correct DAHS tag)
- Confirm scaling (mA/ppm/unit conversion) matches analyzer configuration
- Confirm timestamps (NTP/time sync) and timezone settings
- Confirm validity flags during calibration and fault conditions
- Confirm data storage continuity (no gaps during normal operation)
When you see “Data Gaps”
- Check analyzer comm status and I/O health
- Check switch port logs (if available) and physical cable
- Check DAHS service restart logs / PC uptime
- Check for IP conflicts / DHCP changes
- Verify time sync to NTP server
If “values look correct in analyzer but wrong in DAHS” — suspect scaling, basis conversion,
or tag mapping first. Don’t recalibrate blindly.