Electromechanical counters and electromechanical timers typically accept electric or electronic inputs to operate a mechanical display, such as rotating wheels or knobs.
A counter is a complete instrument for detecting, totalizing, and indicating a sequence of events.  A timer is a device for automatically starting, or stopping a machine or other device.  Many of these instruments can perform both counter and timer functions.   Electromechanical counters and electromechanical timers can be either single function or multi function, or programmable for more than one function.  Electromechanical counters and electromechanical timers can be up direction, down direction, or bi-directional.  Up directional counters can advance forward (UP) in its counting sequence.  Down directional counters can advance backward (DOWN) in its counting sequence.  A bi-directional counter can advance forward or backward (UP or DOWN) in its counting sequence.

Electromechanical counters and electromechanical timers can have many different functions.  These include arithmetic functions, controller, batch counter, count totalizer, event counter, preset, pulse counter, delay cycle, delay on timer, delay off timer, one shot timers, interval delay timer, recycle timer or percentage timer, frequency counter, position indicator, ratemeters or tachometers, and time meters or indicators (clocks).  Arithmetic functions can include sum, difference, multiply, square root, etc.  A controller has outputs to regulate or control equipment based on sensor inputs or preset limits.  Batch counters count up only and are usually presettable so that when the required number of batches or pieces has been completed, the process can automatically stop.  A count totalizer is generally, a counter that can accumulate counts but cannot control a machine. Some totalizers are presettable, but their primary function is to keep track of counts over a relatively long period of time.  An event counter is a unit that counts the occurrences of a certain condition.  Preset counters (or predetermining counters) can control an external circuit when its counted total matches user-entered preset limits.  A pulse counter is used to count a momentary sharp change in current and voltage. With a delay cycle timer when voltage is applied to the input terminals, the time delay cycle starts.  In a one shot timer when power is applied to the timer, the contacts change position immediately and remain changed for the set period of time after the timer has received power.  Interval delay is opposite to delay on, in that the relay is energized immediately on application of the supply or closure of switch input and goes off at the end of the period.  In the recycle timer circuit, the closing of the control switch starts the cycling function.  A frequency counter is a unit for displaying frequency, the number of cycles per second of a waveform. The unit of frequency is Hertz (Hz).  A position indicator can accept, process, and display angle or travel data.  A rate meter is a device that monitors and displays rate.  Time totalizers or indicators are typically used in applications for display of elapsed process time or tracking running time of factory machinery.  Resets can be none, manual, remote, or auto reset.

Electromechanical counters and electromechanical timers typically accept electric or electronic inputs to operate a mechanical display, such as rotating wheels or knobs.
A counter is a complete instrument for detecting, totalizing, and indicating a sequence of events.  A timer is a device for automatically starting, or stopping a machine or other device.  Many of these instruments can perform both counter and timer functions.   Electromechanical counters and electromechanical timers can be either single function or multi function, or programmable for more than one function.  Electromechanical counters and electromechanical timers can be up direction, down direction, or bi-directional.  Up directional counters can advance forward (UP) in its counting sequence.  Down directional counters can advance backward (DOWN) in its counting sequence.  A bi-directional counter can advance forward or backward (UP or DOWN) in its counting sequence.

Electromechanical counters and electromechanical timers can have many different functions.  These include arithmetic functions, controller, batch counter, count totalizer, event counter, preset, pulse counter, delay cycle, delay on timer, delay off timer, one shot timers, interval delay timer, recycle timer or percentage timer, frequency counter, position indicator, ratemeters or tachometers, and time meters or indicators (clocks).  Arithmetic functions can include sum, difference, multiply, square root, etc.  A controller has outputs to regulate or control equipment based on sensor inputs or preset limits.  Batch counters count up only and are usually presettable so that when the required number of batches or pieces has been completed, the process can automatically stop.  A count totalizer is generally, a counter that can accumulate counts but cannot control a machine. Some totalizers are presettable, but their primary function is to keep track of counts over a relatively long period of time.  An event counter is a unit that counts the occurrences of a certain condition.  Preset counters (or predetermining counters) can control an external circuit when its counted total matches user-entered preset limits.  A pulse counter is used to count a momentary sharp change in current and voltage. With a delay cycle timer when voltage is applied to the input terminals, the time delay cycle starts.  In a one shot timer when power is applied to the timer, the contacts change position immediately and remain changed for the set period of time after the timer has received power.  Interval delay is opposite to delay on, in that the relay is energized immediately on application of the supply or closure of switch input and goes off at the end of the period.  In the recycle timer circuit, the closing of the control switch starts the cycling function.  A frequency counter is a unit for displaying frequency, the number of cycles per second of a waveform. The unit of frequency is Hertz (Hz).  A position indicator can accept, process, and display angle or travel data.  A rate meter is a device that monitors and displays rate.  Time totalizers or indicators are typically used in applications for display of elapsed process time or tracking running time of factory machinery.  Resets can be none, manual, remote, or auto reset.

Important display characteristics to consider when specifying electromechanical counters and timers include the number of digits or characters and the height of the digits.  The number of time ranges on counters and timers are single or multiple.  Single time ranges may be fixed or programmable.  Timers with multiple time ranges can be programmed for multiple ranges.  A minimum and maximum time setting must also be specified. 

Advanced specifications to consider when searching for electromechanical counters and electromechanical timers include input channels, count frequency, signal input types and sensor & specialized inputs.  Outputs tend to be voltages or switches and relays.  Mounting types include stand-alone, DIN rail mount, panel or flange mount, PCB mount, portable, and rack mount.  Common features include explosion proof, audible or visual alarms, programmable engineering units, and data loggers or recorders.  An important environmental parameter to consider is the operating temperature.