Panel Meter for Dual-Channel Pulse Input Totalizer Applications P/N L61218FR

Dual-Channel Totalizer Panel Meter Frequently Asked Questions

How is a channel set up to count down instead of up?

Countdown operation is configured simply by entering a negative scale factor for that channel — no separate mode selection is needed. The channel then counts from its preset value down toward zero (or another specified limit) rather than counting up.

What happens to accumulated totals if the meter loses power?

Totals are stored in non-volatile memory specifically so they're retained through a power interruption, rather than resetting to zero when the meter powers back up.

How does up/down totalizing on a single channel actually work?

Channel A does the counting, while a direction signal applied to Channel B dynamically determines whether Channel A adds or subtracts each pulse — for example, tracking total volume correctly even when flow through a turbine meter temporarily reverses.

What hardware is needed to handle two independent fill operations with preset stop points?

A dual setpoint relay board is the minimum recommended complementary option, since each channel's count-to-preset (or count-down-to-zero) event needs a relay output to actually stop or trigger the corresponding fill operation.

How is machine utilization or duty cycle percentage actually calculated by this meter?

On the Extended counter, Channel A is wired to switched AC (only energized when the machine is running) while Channel B is wired to the continuous AC line reference. The meter displays the A/B ratio with a 100 multiplier, so the result reads directly as a percentage of time the machine was actually running relative to total elapsed time.

Can this meter display total volume while also showing instantaneous rate?

Yes, on the Extended version — Channel A can display total while Channel B displays rate, with the operator toggling between them via a front-panel pushbutton, which is well suited to flow applications where both cumulative volume and current flow rate matter.

Does totalizing by inhibit require special wiring, or is it a software setting?

It's a configuration setting on the Extended counter — applying a signal to Channel B temporarily pauses Channel A's totalizing without needing additional external logic or relays, useful for scenarios like counting AC line cycles for elapsed run-time only while a process is actually operating.

Can totals and alarm status be sent to a PLC or SCADA system rather than only viewed locally?

Yes — totals and alarm data can be transmitted via RS232 or RS485 (Modbus RTU or Laurel ASCII), and displayed totals can also be sent as an isolated 4-20 mA or 0-10V analog output.

Can a signal conditioner board be swapped without recalibrating the whole meter?

Yes. Calibration factors are stored in EEPROM on the signal conditioner board and can be scaled via software to accommodate external shunts, which is specifically what allows a board to be field-replaced without a full meter recalibration.

Is RS485 useful when multiple totalizing controllers are used together in one system?

Yes — RS485 supports a single data line addressing multiple controllers, which simplifies setup and monitoring of a mixing operation or multi-line process where several totalizers need to be checked or configured from one location.

Dual-Channel Totalizer Questions From the Field

Should I be concerned about wearing out the non-volatile memory on a totalizer that saves its count very frequently?

Yes, this is a genuinely documented concern for high-frequency pulse-counting applications — EEPROM and similar non-volatile memory technologies are commonly rated for around 100,000 to 1,000,000 write cycles per cell, and an application that saves an updated total every few seconds (rather than periodically or only on power-down) can approach that limit over the life of the equipment. Confirming how frequently your specific totalizing application actually triggers a save operation, rather than assuming "non-volatile" means unlimited writes, is worth doing for very high-cycle counting applications.

If a totalizer saves its count only periodically rather than after every single pulse, could I lose counts during a power failure?

This is a real and commonly discussed tradeoff in totalizer and counter design — saving less frequently extends memory life but risks losing the counts that occurred between the last save and a sudden power loss, while saving after every pulse maximizes accuracy but accelerates memory wear. Understanding which approach a given totalizer uses matters for applications like custody transfer or billing where every count needs to be accounted for.

My duty-cycle percentage calculation (A/B x 100) reads over 100% — what would cause that?

A duty-cycle ratio reading above 100% generally indicates the two channels aren't actually referencing what's intended — for example, if Channel A (meant to be switched, only-when-running AC) is somehow seeing more line cycles than Channel B (the continuous reference), the underlying assumption that A is a subset of B has been violated. Double-checking that Channel A is genuinely wired to switched power and Channel B to the continuous line reference, rather than the wiring being reversed or miswired, is the standard first check.

Why does my up/down totalizer's running total not match what I calculate by hand from known fill and drain cycles?

This is commonly traced to the direction signal on Channel B not being clean or reliable at the exact moments direction actually changes — if there's any ambiguity or noise on the direction signal during a transition, a batch of pulses right around that transition can be counted in the wrong direction. Reviewing the direction signal's behavior specifically during transition moments (rather than during steady, one-direction operation) with a scope helps isolate this from a scaling or wiring problem elsewhere.

Can I run two completely independent fill operations off one dual-channel totalizer, or do they interfere with each other?

They're designed to run independently — each channel (A or B) has its own scale factor, preset, and count direction, so two separate fill operations can genuinely run in parallel on the same physical meter without interfering, provided each has its own dedicated relay output from the dual setpoint board to actually control its respective fill valve or process.

Why does my total reset to zero at a value lower than the meter's stated maximum display range?

This is commonly traced to a configured preset or rollover value set below the meter's actual maximum capacity, often left over from an earlier, lower-volume application — reviewing and updating the configured preset or reset threshold against current actual process volumes resolves an unexpectedly early reset.

Does the totalizer's stored total survive a battery or power loss the same way whether it's a small or large accumulated value?

Non-volatile memory retention isn't generally affected by the magnitude of the stored value — a large accumulated total is retained through a power loss the same reliably as a small one, since the memory technology stores the value as data regardless of its numeric size. The concern with non-volatile storage is write frequency and cycle count over the product's life, not the size of the number being stored at any given moment.

My machine utilization percentage seems to drift slightly over very long measurement periods even though the machine's actual run pattern hasn't changed — why?

Small cumulative rounding in the underlying pulse-count-based ratio calculation is a commonly cited contributor to this kind of slow drift over very long accumulation periods, since a ratio calculated from two very large accumulated counts can be more sensitive to small rounding at each individual count event than a ratio calculated over a shorter period. Periodically resetting and re-baselining the measurement period, rather than running one continuous multi-year accumulation, is a practical way to keep this kind of drift from becoming meaningful.