RCM Digital Flow Meter

Digital Flow Meter

• Digital Display Rate & Total – Option RW3
• Remote Digital Display Rate & Total – Option RD-1

The RCM Digital flow meter display is a 2 wire loop powered 4-20mA DC transmitter features 7 digits for flow rate and 11 digits for accumulated total. On-screen engineering units are easily configured, while different units for flow rate and total can be displayed simultaneously. A wide selection of options further enhances this models capability. Optional back-lighting is available for easy viewing.

Wet/wet differential pressure sensor is protected by an isolated stainless steel diaphragm for measuring liquids, gases and conductive flow media.

The digital display can be connected as a remote display (option DR-1) to our 4-wire transmitter output option W (4-20mA linear output signal), 2-wire loop powered transmitter option W2 or W3 (4-20mA loop powered signal) output is proportional to flow rate squared or our 2-wire loop powered transmitter option RW3 which is self-contained and complete.

RCM Industries has been manufacturing quality flow measuring products for over 35 years for end-users and OEM applications.

Standard Features:

• 15 Point Linearization of Flow Curve
• Displays Instantaneous Flow Rate, Total & Accumulated Total
• Large 17mm (0.67) Digit for Flow Rate or Total
• Operational Temperature -30 to 80C (-22 to 178F)
• Rugged Enclosure IP67/NEMA 4X Rated **
• Wet / Wet Differential Pressure Sensor
• Amber or Green Backlighting (Optional)

** IP67 indicates that this enclosure is dust-tight and water-tight up to 1 meter immersion depth.

** NEMA 4X Enclosure Characteristics:

• Indoor or outdoor use, including offshore applications
• Protection against windblown dust and rain
• Protection from splashing water and hose-directed water
• Corrosion-resistant

Standard Specifications:

• Accuracy: ± 3% F.S.
• Repeatability: ± 1% F.S.
• Pressure Max.: 180 psig (12.6 kg/cm2)
• Pressure Min.: 10 psig (0.67 kg/cm2)
• Temp. Max.: 212ºF (100ºC)
• Temp. Min.: -30ºF (-34ºC)
• IP67 / NEMA 4X Rated Enclosure

Electrical Rating:

Power Input:

100mA, 24Vdc power supply 20-30Vdc (Not Included)
Input loop powered from 4-20mA signal. Voltage drop max. 2.6V

Display:

Rate Display:
High intensity reflective numeric and alpha numeric LCD, UV resistant
User definable, 8 times/sec – 30 secs.
Password Protection
7 and 11 digit various symbols and measuring units

Environmental:

Operating Temperature: -30ºF (-34ºC) to 212ºF (100ºC)
Humidity: 0-90% Noncondensing

Accuracy:

0.5% F.S. (Non-linearity, Repeatability and Hysteresis
Stability:
0.5%F.S./year

Signal Inputs:

Full Scale Range: 4 to 20 mA DC
Loop Voltage Drop: 2.6 Volts Max. at 20mA
Update Time: 4 times/sec.
Span: 0.001/999,999 with available decimal position
16 Bit resolution, error < 0.01mA/+- 0.05% F.S.
Low cutoff supplied to inhibit indications at low flow rates

Signal Ouput:

The pulse output transmitting accumulated total
Type: one passive transistor output (NPN)
Max. 500Hz pulse length user definable between 1 msec up to 10 sec.

Calibration & Operation:

Input Scaling: Via front keypad
Decimal Point: Via front keypad
Reset Input: Via front keypad
Keypad: 3 tactile feedback keys

Wiring Overview

This document explains the installation, wiring, calibration, and programming of the Digital Display Option R (built-in) and the DR-1 remote display accessory for Flo-Gage systems.
The display processes a 4–20 mA DC signal to show flow rate and totalization, with options for linear or square root scaling and pulse output for remote totalizers.

1. Installation & Wiring

• General:

• Designed for direct mounting in the Flo-Gage housing or as a remote display.
• Displays up to 4½ digits for rate and 8 digits for totalization.
• Provides isolated open-collector pulse output for remote totalizing or external devices.
• Requires a 4–20 mA loop-powered signal from transmitter options W2 or W3.

• Built-in and Remote Wiring:

• Includes wiring diagrams for both internal and external (DR-1) configurations.
• Caution: Pulse output polarity must be correct; voltages over 30 V can damage the circuit.
• Figures illustrate pulse output conversion and waveform.

2. Programming Definitions

The programming menu allows customization of display and scaling functions.
Key programmable parameters include:

• ent code: Password entry (if lock is on).
• clr tot: Clear totalizer.
• 3 or 4: Choose 3.5 or 4.5 rate digits.
• dec loc / tdec: Set decimal point locations for rate and totalizer displays.
• tot desc / rat desc: Select engineering units (GAL, LIT, FT³, M³) and rate time base (/sec, /min, /hr).
• input: Choose linear or square root extraction.
• rate lo / rate hi: Define the 4 mA and 20 mA corresponding rates.
• lo cut: Set low cutoff percentage.
• pulseout: Set pulse output divider (÷1, ÷10, ÷100, or off).
• cal / cal LO / cal HI: Calibration steps for input scaling.
• loc code / loc unit: Configure access lock and password.

3. Programming Flow

A step-by-step flowchart details how to:

• Enter and navigate programming mode.
• Set display resolution, units, scaling, and calibration.
• Adjust pulse output, low cutoff, and locking options.
• Save settings before returning to run mode (do not remove loop power mid-program).

4. Error Codes

5. Battery Replacement

• Battery: Panasonic BR2330 (3V Lithium).
• Maintain loop power during replacement to preserve calibration.
• Reinitialize and recalibrate if loop power is lost.
• Battery polarity must be correct (+ on top).

6. Dimensions

• DR-1 Remote Display: 4.92″ x 4.21″ front face
• Panel-mounted with four screws,
• Terminals accessible beneath cover.

7. Specifications

Power & Display

• Loop powered (4–20 mA); internal 3V lithium battery for memory.
• Rate: 3.5/4.5 digits, updates every 2 seconds.
• Totalizer: 8 digits up to 99,999,999.
• Decimal and unit selection flexible.
• Low-battery indicator (“BAT” flashes).

Environmental

• Operating range: -4°F to +158°F (standard) or -22°F extended.
• Humidity: 0–90% non-condensing.

Accuracy

• ±0.1% full scale, ±1 count.
• Temp drift: 50–200 ppm/°C.

Inputs

• 4–20 mA signal, reverse-polarity protected, 6V drop max.
• Reset via front keypad or contact closure.
• 16-bit resolution, 1 sample every 2 seconds.

Pulse Output

• Opto-isolated open collector.
• 30V max, 25 pulses/sec max.
• Divider: ÷1, ÷10, ÷100, or off.

Lockout Options

• Software password (4 digits).
• Hardware jumper for sealed lockout.

In summary

The Digital Display Option R / DR-1 is a robust, programmable, loop-powered flow display capable of displaying rate and total flow, offering scalable pulse output, lockout protection, and simple front-panel calibration. It’s ideal for applications requiring accurate digital indication and remote totalization of 4–20 mA signals