PENTA P6000 6-Digit Frequency Meter

SEVEN OPERATING MODES

1. FREQUENCY, TACHOMETER, RATE MODE
In the frequency mode, the P6000 provides a 14-decade measurement range with 6-digit resolution from below 1 µHz (36-day period) to 7 MHz. Exceptional flexibility of operation is made possible by 6-digit software multiply or divide, software averaging, and software-selectable number of digits to the right of the decimal point. This allows the P6000 to display frequency in Hz, kHz or MHz, to be used as a tachometer with display of RPM, or to be used as a rate meter for display of flow or speed. Programmable zero offset allows the P6000 to be used with transducers with frequency output.

A major feature of the P6000 is its ability to measure very low frequencies with 6-digit resolution in times as low as 50 ms + 1 signal period. This is achieved with a gate time setting of 0.00 sec and communications at 9600 baud. Slower read rates may be programmed and will provide a mathematical average over multiple signal periods.

The ability to combine low-frequency measurement with high read rate makes the P6000 ideal for monitoring power line frequency and low rates of speed or flow. For instance, the P6000 can display 60 Hz line frequency at 15 readings/sec. It can display accurate flow rate in units of flow even if there are several seconds between pulses from a positive displacement flowmeter.

To measure frequency, the P6000 counts the number of signal periods during a preprogrammed gate time and then extends this gate time dynamically to eliminate any partial signal periods. It also counts the number of 11.059 MHz crystal-clock periods during the same measurement time. The ratio of signal periods to clock periods provides signal frequency; the ratio of clock periods to signal periods provides signal period. In case of periods over 2 sec, which may indicate very low frequency or a complete stoppage of the signal source, the P6000 may be programmed to wait for the next end-of-period pulse or to automatically reset frequency to zero.

2. FB/FA FREQUENCY-RATIO MODE
The P6000 can be used as an FB/FA frequency-ratio meter with FB and FA up to 7 MHz. In case of low frequencies, the P6000 achieves exceptional accuracy in minimum time by correcting for partial signal periods in FB during the actual gate time. The frequency ratio capability is ideal for monitoring the relative speed of shafts, conveyor belts and other moving machinery. In combination with display offset, it can also be used to display draw.

3. PULSE TOTALIZER MODE
The P6000 can be used as an up-counting totalizer (with positive scale factor) or a down-counting totalizer (with negative scale factor) for rates up to 7 MHz. The display capacity is -99,999 to 999,999 counts. In case of over-range, the display automatically converts to exponential format with correct readings up to 9.99 x 10⁹, which is displayed as 9.99 E9. An external signal can repetitively gate input pulses without error in gated counts. In the event of AC power loss, the latest reading is automatically saved in non-volatile RAM and is restored upon return of power.

4. PERIOD/PERIOD-AVERAGE MODE
The P6000 can be used as a period or period-average meter by counting the number of clock pulses during a pre-programmed gate time, which is extended to eliminate any partial period. The nominal gate time is programmable from 10 ms to 99.99 s and can be extended dynamically by the signal period to 36 days. If the preprogrammed gate time is longer than one period, the P6000 automatically calculates the average period, thereby compensating for any jitter in the individual periods.

5. A-TO-B TIME INTERVAL/ TIME-INTERVAL AVERAGE MODE
The P6000 can be used to measure the time interval or average time interval between the rising or falling edges of two signals. The meter counts the number of clock pulses in time intervals during a preprogrammed gate time. If the pre- programmed gate time is so long as to contain multiple time intervals, the P6000 automatically calculates the average interval, thereby compensating for any jitter in individual intervals. The time-interval-average capability allows ex-tremely accurate phase measurement at a known frequency. A special configuration is available which converts the P6000 to a phase meter.

6. PROCESS METER MODE
With the addition of an optional analog-to-frequency signal conditioner board, the P6000 can become a process meter with 99.9% accuracy for 4-20 mA, 0-5 V or 0-10 V analog signals. Benefits of the P6000 as a process meter include the two setpoints, RS-232 communications, programmable zero and span, and programmable time for signal averaging.

7. INTEGRATING TOTALIZER MODE
With the analog-to-frequency signal conditioner board, the P6000 can also be used as a 6-digit totalizer for 4-20 mA, 0-5 V or 0-10 V signals. For example, it can totalize the 4-20 mA signal from a flowmeter to display total volume in liters or gallons. It can totalize the 0-10 V signal from a power meter to display kilowatt-hours. In either example, the P6000 can easily be scaled to read out directly in dollars.

RS-232 communications and modem support are built into the P6000 for remote programming, remote diagnostics and data transmission.

LOCAL OR REMOTE PROGRAMMING

1. FRONT-PANEL PROGRAMMING
The P6000 can be programmed manually at the front panel, which provides five programming keys and alphanumeric prompting through the LED display. If desired, all setup parameters can be stored in non-volatile memory. To prevent unauthorized or inadvertent program changes, the P6000 provides four levels of front-panel lockout using push-on jumpers. The front panel can be locked out completely, be locked out except for setpoints, or be fully usable except for fine-calibration of the crystal clock. Saving program changes in non-volatile memory can also be locked out, so that previously stored setup parameters can always be recalled.

Once the program is stored in non-volatile memory, an optional front panel without keys can be substituted for the standard front panel with keys.

2. REMOTE PROGRAMMING
The P6000 can also be programmed remotely by down-loading setup parameters from a host computer via RS-232 using direct wiring or a modem. It is well suited for ATE and other computer-controlled applications, since the host computer or programmable controller can dynamically change all setup parameters, including setpoints, and receive data via RS-232. To aid in programming, an IBM PC compatible 5i1/4 inch floppy disk with a menu-driven setup program is available as a low-cost option.

3. PREPROGRAMMED VERSIONS The P6000 can be ordered fully configured and programmed from Newport or its authorized distributors, with the program stored in non-volatile memory. Such preprogrammed units can later be modified by the user through the front panel or via RS-232.

DATA, ALARM AND CONTROL OUTPUTS
In addition to RS-232/20 mA ASCII communications and three open-collector outputs (which are standard and implemented on the main board), the P6000 offers a choice of three upper-board control options for data, alarm and control. Depending on the choice of operating mode and signal conditioner (pulse or analog), the output can reflect rate, time, frequency ratio or analog level.

Isolated parallel BCD output allows the P6000 to be interfaced to programmable controllers and to Newport's Model 820A printer. The combination of a P6000 with an 820A provides a low-cost datalogging system where the readings are tagged with time and date.

Dual 8 A Form C relays allow the P6000 to switch resistive loads up to 2 kW for alarm and control applications.

Isolated analog output provides jumper selection of 0-10 V or 4-20 mA and adjustable zero and span. The 0-10 V output is ideal to drive a stripchart recorder. The 4-20 mA output effectively turns the P6000 into an isolated transmitter.

In totalizer mode, the P6000 counts positive or negative edges. An external-gate signal willl not produce a false count, as in conventional counters.