Field data, right now
Getting data from field devices into operational systems in real time sounds straightforward until you are standing in a server room at midnight wondering why the pipeline that worked fine in staging produces nothing in production. Field data integration fails in ways that are specific, predictable, and largely avoidable.
The field environment is not the office network
Field devices — sensors, PLCs, meters, RTUs — operate under conditions that IT infrastructure does not. Intermittent connectivity is normal, not exceptional. Power cycling happens without warning. Clocks drift. Firmware is old and stays old. The assumption that a device will be reachable when you need it is wrong.
Any integration that does not account for these conditions will fail in the field, regardless of how well it works on the bench.
Pull versus push
The choice between pull (your system queries the device) and push (the device sends data when it has something) has significant implications for field deployments.
Pull is simpler to implement and easier to reason about, but requires the device to be reachable at query time and does not scale well with large device counts or high polling frequencies.
Push reduces load on the integration layer and tolerates intermittent connectivity better, but requires the device to buffer data and retry sends, capabilities that not all field hardware has.
In practice, many field deployments use a hybrid: a local edge collector that pulls from devices on the local network and pushes aggregated data upstream over whatever WAN connectivity is available.
Timestamps are not free
Field data without reliable timestamps is nearly useless for operational purposes. Device clocks drift, NTP is often unavailable on isolated field networks, and some hardware has no real-time clock at all.
The correct approach is to timestamp at the point of collection, not at the point of receipt. Record when the collector observed the data, not when it arrived at the central system. If device timestamps are available and trustworthy, record both.
Summary
Field data integration is reliable when it accounts for the actual conditions of the field environment: intermittent connectivity, unreliable clocks, and hardware that cannot be updated. Treating these as edge cases rather than baseline assumptions is the primary cause of field integration failures.