A pump-off controller can decide when to rest a rod-pumped well in two very different ways. The sophisticated way infers the downhole condition from load and position data; the simpler way just runs the pump on a clock. This guide is about that second way - timer mode - and how it differs from the load-based control the general pump-off controller page describes. It covers how run and off intervals are configured, what percent-runtime means, the role of a malfunction timer, and when an operator chooses timer mode over dynamometer-based pump-off detection.
POC Timer Mode in one line: POC timer mode is a configuration of a pump-off controller that cycles a rod pump on preset time intervals rather than by sensing the downhole pump condition. The operator sets how long the pump runs and how long it idles, often expressed as a percent runtime, and the controller repeats that on-off cycle. It is chosen when the well is simple or stable, or when the load-sensing hardware for dynamometer-based pump-off detection is not available.
In timer mode the controller's logic is deliberately simple: run the pumping unit for a set period, then shut it off for a set period, then repeat. The run interval is chosen to be long enough to draw the accumulated fluid down without pumping the well off hard, and the idle interval is chosen to let the fluid level in the well recover before the next run. Setting these two intervals is the whole of the configuration - there is no load sensing involved, just two durations that define the cycle. An operator arrives at reasonable values from knowledge of how quickly the particular well produces and recovers, often refined by observation over time.
Percent runtime is a convenient way to express the balance between those two intervals. It is the fraction of total time the pump actually runs - a well running ten minutes out of every twenty is at fifty percent runtime, one running fifteen of every twenty is at seventy-five percent. Percent runtime is useful because it summarizes the cycle in a single number that maps directly to how hard the well is being worked and roughly how much it produces: a well that needs a high percent runtime is being pumped nearly continuously, while a low percent runtime means the well fills slowly and spends most of its time resting. Operators and controllers often track and adjust the cycle in terms of this percentage.
Some timer-mode setups add a degree of adaptation on top of the fixed intervals. Rather than holding the idle time rigidly, a controller may nudge the off period based on trends, lengthening idle time if the well appears to be producing less and shortening it if the well seems able to support more running. Even so, the defining characteristic of timer mode remains that the cycle is governed by time intervals the operator sets, not by a direct measurement of whether the pump is currently filling with fluid.
Timer mode does not sense the pump, but it still needs to protect the equipment, and a malfunction timer is the main safeguard. The idea is that certain problems show up as abnormal running behavior - a unit that keeps running far longer than any normal cycle should, or one that fails to start when it is supposed to, may indicate a mechanical fault, a stuck condition, or a control problem. A malfunction timer watches for run times that exceed a sane maximum or other timing anomalies, and when one occurs it shuts the unit down and flags the condition rather than letting an abnormal state persist unattended. It is a blunt but valuable backstop for a control scheme that otherwise has no direct feedback from the pump.
Beyond the malfunction timer, timer-mode protection is inherently limited compared to load-based control, and that is the honest trade-off. Because the controller cannot see the pump card, it cannot tell that the well has genuinely pumped off partway through a run interval, so it may keep pumping a pumped-off well until the run timer expires, which is exactly the fluid pound that load-based control exists to avoid. Timer mode manages this risk by choosing conservative intervals rather than by detecting the condition, accepting some inefficiency in exchange for simplicity.
This is why timer mode is best suited to wells where the risk is modest - wells that are stable, that do not pump off aggressively, or where the consequences of an occasional non-ideal cycle are small. On a demanding well, the lack of real pump feedback means timer mode can either overwork the pump or leave production on the table, and the protection the malfunction timer offers, while worthwhile, is no substitute for actually sensing the downhole condition.
An operator chooses timer mode over dynamometer-based pump-off detection for a few practical reasons. The most common is hardware: load-based control needs a load cell and position sensing to build the dynamometer card the controller analyzes, and if that instrumentation is not installed or has failed, timer mode is the fallback that still lets the well be cycled sensibly. Cost and simplicity also drive the choice on lower-value or straightforward wells, where the expense and complexity of full pump-off detection is hard to justify. And timer mode serves as a reliable default: a well can run on timers while load-based control is being commissioned or when a sensor problem takes the sophisticated mode offline.
Timer mode also fits wells whose behavior is predictable enough that a clock does a good-enough job. A steady well that fills at a consistent rate can be cycled well by fixed intervals, and the added precision of pump-off detection buys little. The decision is ultimately about matching the control scheme to the well's value and difficulty - reserving the more capable, more expensive load-based mode for the wells that genuinely need it, and running the simple, robust timer mode where it suffices.
Either way, a cloud SCADA makes timer mode far more manageable across a field. Merobix reads pump-off controllers over field protocols such as Modbus and DNP3, so run times, idle times, percent runtime, cycle counts, and malfunction-timer trips become monitored values, and the timer settings can be adjusted remotely without a trip to the well. That matters because timer mode's weakness is its lack of feedback: watching percent runtime and production trend on a dashboard lets an operator catch a well whose cycle has drifted out of tune, spot a malfunction trip promptly, and re-set intervals from the office. The controller keeps the simple clock running locally, while the platform supplies the fieldwide oversight that timer mode on its own lacks.
Percent runtime is the fraction of total time the pump actually runs in its on-off cycle - a well running ten minutes out of every twenty is at fifty percent. It summarizes how hard the well is being worked in a single number: a high percent runtime means the well is pumped nearly continuously, while a low value means it fills slowly and rests most of the time. Operators often track and adjust the timer cycle in terms of this percentage.
Most often when the load cell and position sensing needed for dynamometer-based detection are not installed or have failed, so timer mode is the fallback that still lets the well be cycled. It is also chosen on stable, predictable, or lower-value wells where the cost and complexity of full pump-off detection is hard to justify, and as a reliable default while load-based control is being commissioned or repaired.
It is the main safeguard in a control scheme that has no direct feedback from the pump. The malfunction timer watches for abnormal running behavior, such as a unit running far longer than any normal cycle or failing to start when expected, and shuts the unit down and flags the condition when it detects one. It is a blunt backstop that catches gross faults but cannot detect a genuine pump-off the way load-based control can.
This page references the protocol specifications published by the organizations below. Editions, product capabilities, and documentation change over time - confirm current requirements and specifications directly with the source.
Last reviewed: July 27, 2026. Merobix is not affiliated with, endorsed by, or sponsored by these organizations; their names are used only to identify the standards and products discussed.
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