Micron MM50 Series True RMS AC Voltage & Current Meter, 1 Cycle Update at 50/60 Hz.

200 mV - 600 V and 2 mA - 5 A full-scale ranges

The Micron True RMS meter is a 60,000 count digital panel meter with exceptional performance at half the price of a bench top meter. It can measure true RMS voltage or current of AC signals where there is considerable distortion of the waveform, such as rectifier outputs or waveforms chopped by an SCR, TRIAC or transistor circuit, as illustrated.

• True RMS readings in 0-16 ms after completion of one input signal cycle allow anomalies to be detected and alarmed before they become expensive problems. Fast on/off control and alarm can be achieved with optional dual or quad relays, either contact or solid state. The meter can also capture peak and valley readings that occur at the nominal rate of 50/60 Hz.
• Accuracy to 0.1% of full scale for signals from DC to 10 kHz and signal amplitudes down to 0.1% of full scale. The crest factor (Vp / Vrms) is 3.0 at full-scale Vrms of 20,000 counts and a Vp of 60,000 counts. The meter starts to flash overrange at 132% of full scale Vrms , at which point the available crest factor is 60,000 / 26,400 = 2.27. Meaningful readings with rated resolution continue to be obtained up to 212% of full scale Vrms (42,433 counts) for sinusoidal signals, at which point the available crest factor is 1.414. For safety reasons, the maximum RMS input signal should never exceed 600V or 5A. ETL certification is for a maximum voltage of 300 Vrms.

AC or DC coupling is jumper selectable on the signal conditioner board. AC coupling accommodates signals from 10 Hz to 10 kHz and is suitable for applications such as measuring AC ripple on a DC power supply. DC coupling accommodates signals from 0 to 10 kHz. Multiple integral cycles are averaged for signals above 50/60 Hz. A single cycle is captured for signals from 3 Hz to 50/60 Hz. Below 3 Hz and at DC, the capture rate is 3/sec.

Use with current Transformers. High common mode rejection allows stable readings with current shunts located on the high side of the line. Five amp input capability allows the output of 5A current transformers to be applied directly to the meter, with no need for a stepdown transformer. The meter reading can easily be scaled for the current transformer ratio. Digital filtering is selectable for noisy signals.

Designed for system use. Optional plug-in boards for communications and control include Ethernet and other serial communication boards, dual or quad relay boards, and an isolated analog output board. Microns may be powered from 85-264 Vac or optionally from 12-32 Vac or 10-48 Vdc. The display is available with red or green LEDs. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can be locked out for simplified usage and security. All power and signal connections are via UL / VDE / CSA rated screw clamp plugs.

Using Micron Meters to Synchronize Two Motor Generators

Successful synchronization of two motor generators requires that the voltage outputs of the generators be close to each other, that the two frequencies be identical, and that the voltage waveshapes be in phase.

• The two voltages can be measured by two Micron AC RMS Voltmeters, which offer 200.00 V and 600.0 V ranges. Or a single meter can be multiplexed by using an external toggle switch.
• Two frequencies A & B can be measured to six-figure accuracy by a single Micron Dual Channel Counter, where each channel monitors a generator. The two AC neutrals must be tied to meter ground. Pressing a front-panel key toggles the reading between the channels. The meter can also display frequency A - frequency B, or frequency A / frequency B without toggling.
• Phase angle can be measured using the Micron Phase Meter.

Using Micron Meters and Counters to Instrument an AC Line

 

Why Measure AC Power?

Many AC loads, such as electrical motors, will only operate reliably if the AC line voltage and frequency are within specified tolerances; otherwise permanent damage to expensive plant equipment may occur. Drops in line voltage or frequency may indicate an excessive load and the possibility of equipment damage. Micron meters and counters are low-cost means to instrument and alarm AC power lines with great accuracy:

• AC RMS Voltmeter and Ammeter, as documented in this page. True RMS capability allows the display of RMS voltage for non-sinusoidal waveshapes, such as square waves from a UPS. A built-in 5 A range can be used to display currents up to 5.000 A with 1 mA resolution or accept the output of 5 A current transformers. The 200.00 mV range can be used with external current shunts. With either transformers or shunts, scaling of the input current is easily accomplished via the meter's front panel pushbutton switches.
• Frequency Meter. Inverse period is used to determine AC line frequency to six-figure accuracy (60.0000 or 50.0000) in a few line cycles plus 30 ms.
• Phase Angle & Power Factor Meter. Two signals with identical periods are applied to Channels A and B. A phase angle resolution of 1%, 0.1% or 0.01% is selectable. Accuracy is .01% up to 100 Hz, .1% at 1 kHz, and 1% at 10 kHz.

Display
Readout	5 LED digits, 7-segment, 14.2 mm (.56"), red or green
Range	-99999 to 99999 or -99990 to 99990 (count by 10)
Display Update Rate	3.75/s at 60 Hz power, 3.1/s at 50 Hz power
Indicators	1 LED lamp per relay setpoint
Crest factor Vp / Vrms	3.00 at full scale range
Output Update Rate
A-to-D rate	60/s at 60 Hz power, 50/s at 50 Hz power
Signals > 50/60 Hz	60/s at 60 Hz power, 50/s at 50 Hz power
Signals 3 to 50/60 Hz	Signal frequency
Signals DC to 3 Hz	3 per second
Maximum Signal
Max applied voltage	600 Vac for 2, 20, 200, 600V ranges, 35 Vac for 0.2V range
Current protection	25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5A
Power Module Power Module Specs. × Power Module Micron MM50 Series Power Modules 85-264 Vac / 90-300 Vdc, or 12-32 Vac / 10-48 Vdc Power Input Isolated 5, 10 & 24 Vdc Transducer Excitation Output 12-32 Vac or 10-48 Vdc power input board(left) 85-264 Vac or 90-300 Vdc power input (right) Key Features Lightweight, high-frequency switching power supply design. 85-264 Vac or 90-300 Vdc power version 12-32 Vac or 10-48 Vdc power version Isolated 5, 10 or 24 Vdc transducer excitation output UL Recognized on-board fuse Three selectable isolated excitation outputs Certified to EN 61010-1 (CE mark) and RoHS ETL certified to UL 61010-1 and CSA C22.2#61010-1 Description Micron's MM50 digital panel meters, digital counters and 6-digit remote display offer a choice of two high-frequency switching power supplies. These provide stable, isolated power for instrument operation plus excitation outputs at a substantially reduced weight and over a broader range of input voltages and power frequencies than conventional linear supplies. High voltage AC or DC power. The standard Micron supply accepts power from 85-264 Vac, 47-63 Hz. This allows the same meter to operate worldwide without modification. The supply also accepts 90 to 300 Vdc (high voltage DC operation not ETL approved). Low voltage AC or DC power. An optional low voltage supply operates from 10 to 48 Vdc or 12 to 30 Vac, 47-63 Hz. This supply allows the Micron to be powered from batteries or from 28 Vac, 400 Hz aircraft power (400 Hz operation not ETL approved). Isolated Excitation Output Each power supply provides three jumper-selectable, isolated excitation outputs: 5 Vdc at 100 mA, 10 Vdc at 120 mA, or 24 Vdc at 50 mA. These outputs can be used to power external sensors, transmitters and up to four 350 ohm load cells in parallel, thereby avoiding the need for an expensive external supply. When powering a load cell or potentiometer, a ratiometric operating mode can be selected, where the meter monitors the excitation supply and removes the effects of voltage variation. In addition to the isolated excitation output, regulated 5 Vdc at up to 50 mA is brought out and can be used to power external logic. Wiring of Excitation Output 4-Wire, 4-20mA Transmitter Wiring 2-Wire, 4-20mA Transmitter Wiring With four-wire transmitters, two wires are used to apply 10 or 24 Vdc, and two separate wires are used to sense the transmitter's 4-20 mA output. With two-wire transmitters, the same two wires are used to power the transmitter and carry the 4-20 mA output, which is made to flow across an internal 10 ohm resistor between pins 3 and 4. Both power supplies and their connectors (standard) are designed to UL/IEC/CSA safety standards. The two supplies also do double-duty by providing two connector inputs (A & B) and a digital ground for signals such as meter hold, reset, tare, etc. These signals do not affect power supply operation.   OPERATING POWER   Module PS1 Module PS2 Frequency Power Consumption 85-264 Vac or 90-300 Vdc 12-32 Vac or 10-48 Vdc DC and 47-63 Hz 5.3 W max PROTECTION   Module PS1 Module PS2 Module PS2 On-board fuse rated 0.5A, 277 Vac, UL Recognized On-board fuse rated 2.5A at 250 Vac or 63 Vdc, UL Recognized EXCITATION POWER SUPPLY   Selectable Outputs 5 Vdc ± 5%, 100 mA 10 Vdc ± 5%, 120 mA 24 Vdc ± 5%, 50 mA Ripple Isolation to Power Gound Isolation to Meter Ground 50 mVp-p max 250V rms working, 2.3 kV rms per 1 min test 50 Vp PIN ASSIGNMENT (POWER & DIGITAL CONTROLS)     Close
Voltage, standard	85-264 Vac or 90-300 Vdc
Voltage, optional	12-32 Vac or 10-48 Vdc
Frequency	DC or 47-63 Hz
Power consumption (typical, base meter)	1.2W @ 120 Vac, 1.5W @ 240 Vac, 1.3W @ 10 Vdc, 1.4W @ 20 Vdc, 1.55W @ 30 Vdc, 1.8W @ 40 Vdc, 2.15W @ 48 Vdc
Power Isolation	250V rms working, 2.3 kV rms per 1 min test
Analog Output Module (Optional) Analog Module Specs. × Analog Output Micron MM50 Meter 16-Bit Analog Output Option Module 16-Bit Analog Option Board Key Features 16-bit resolution (1 part in 65,536 or 0.0015% of full scale) 4-20 mA, 0-20 mA, 0-10V, or bipolar -10 to +10V analog output Analog output linearized to reading Analog output isolated to 250 Vac ±0.02% full scale accuracy Scale and offset via meter front panel, RS232, RS485 or USB Certified to EN 61010-1 (CE mark) and RoHS Output derived from filtered or unfiltered signal input 12V compliance at 20 mA CE Mark RoHs Mark ETL Mark Made in the U.S.A. Description A 16-bit analog output option board can turn a Micron 1/8 DIN digital panel meter, counter, timer or remote display into a superb, isolated, linearized transmitter or signal conditioner with exceptional accuracy and high-speed response. The analog output for thermocouples, RTDs and custom curves is linearized to the displayed reading. The analog output can be selected as 4-20 mA, 0-20 mA, unipolar 0-10V, or bipolar -10V to +10V with a 20V span and 0V at mid-range. If a voltage output is selected, output pins 1 and 2 may be reversed to provide reversed polarity. A 16-bit D-to-A converter provides 0.0015% full-scale resolution and ±0.02% full-scale accuracy. The update rate for meters is a fast 60/sec for 60 Hz power or 50/sec at 50 Hz power. The analog output can track the unfiltered signal for fastest response, or a digitally filtered signal for best noise rejection. Isolation from power and signal is provided by a separate power supply in the meter. This supply can drive 20 mA of current into loads up to 600 ohms for 12V compliance. Isolation to signal ground and power ground eliminates problems caused by ground loops. Scaling of the analog output can be via the meter's front panel pushbuttons or a serial digital interface using Instrument Setup software. The displayed readings to produce the low and high analog outputs can be set to any value from -99999 to +99999 for DPMs or from -999999 to +999999 for counters and timers. Depending on your selected output range, simply set the meter reading for low analog output (4 mA, 0 mA, 0V or -10V) and for high analog output (20 mA or 10V). The bipolar -10V to +10V analog output can provide a negative signal for a negative deviation from a setpoint, and a positive signal for a positive deviation. It can also be used for proportional control around a setpoint. For example, if proportional control is desired around 170°C with a ±10°C span, set the -10V output to 160°C and the +10V output to 180°C. The control signal will be 0V at 170°C. Micron DIN rail transmitters come standard with a 4-20 mA, 0-20 mA, 0-10V, or bipolar -10 to +10V analog output with 16-bit resolution. Specifications Electrical Power source Provided by meter Signal source Filtered or unfiltered digitized signal Output linearization Linearized to reading Output Levels (selectable) 4-20 mA, 0-20 mA, 0-10V, -10 to 10V Compliance at 20 mA 12V ( 600 Ω max load ) Compliance at 10 V 2 mA ( 5 kΩ min load) Isolation 250V rms working, 2.3 kV rms per 1 min test Output resolution 16 bits (0.0015% of full scale) Output nonlinearity < 0.01% of full scale Accuracy < 0.02% of full scale Output update rate, DPMs 50 or 60/sec (output may be digitally filtered) Output update rate, counter rate meter Gate time + 30 ms + 0-2 periods Scaling Zero output & full-scale output, DPMs -99,999 to +99,999 counts Zero output & full-scale output, counters -999,999 to +999,999 counts Minimum span 150 counts J4 Pin Assignments Unipolar Connections Bipolar Connections 4-20 mA or 0-20 mA output 1 Reference or Return 1 0-10V output 2 -10V to +10V Output 2 Isolated ground 3 N/C 3     Close
Output levels	4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable)
Current compliance	2 mA at 10V ( > 5 kΩ load)
Voltage compliance	12V at 20 mA (< 60Ω load)
Scaling	Zero and full scale adjustable from -99999 to +99999
Resolution	16 bits (0.0015% of full scale)
Isolation	250V rms working, 2.3 kV rms per 1 min test
Relay Outputs (optional) Relay Module Specs. × Relay Module Micron MM50 Meter Dual or Quad Relay Option Modules Dual 8A Contact Relays Quad 8A Contact Relays Dual 120mA Solid State Relays Quad 120mA Solid State Relays CE Mark RoHs Mark ETL Mark Made in the U.S.A. Description Standard Features Fits all 1/8 DIN Micron DPMs, counters, timers & remote displays Choice of four relay output boards : - Two contact relays - Two solid state relays - Four contact relays - Four solid state relays Contact relays rated 8A at 250 Vac or 24 Vdc Solid state relays rated 120 mA at 140 Vac or 180 Vdc Outputs can be based on filtered or unfiltered signal input Responds in one reading or after programmable delay Selectable operating modes: - Output above or below setpoint - Latching or non-latching - Band deviation or hysteresis around each setpoint Setpoint setup via front panel pushbuttons or a PC Security lockout of front panel setpoint controls Certified to EN 61010-1 (CE mark) and RoHS Electrocontact or Solid State Relays Four optional plug-in setpoint controller boards are available to add control and alarm capability to 1/8 DIN Micron DPMs, counters, timers and remote displays: Two contact relays Two solid state relays Four contact relays Four solid state relays The contact relays are rated for 8A at 250 Vac or 24 Vdc and are recommended for high currents. The dual contact relays are mutually isolated Form C relays and can be wired to be normally open (NO) or normally closed ($0) when not energized. The quad contact relays are normally open (NO) Form A relays and share a common isolated ground in pairs. The solid state relays are rated for 120 mA at 250 Vac or 24 Vdc and are recommended for low currents and frequent switching. They are Form A relays, which are normally open (NO) when not energized. As for the contact relays, the dual solid state relays are mutually isolated, and the quad solid state relays share a common isolated ground in pairs. Operating Modes Operation above or below setpoint. Each relay may be individually programmed to be energized above or below a setpoint, or may be disabled. Latching or non-latching. Each relay may be individually programmed to operate in a latching or non-latching mode. In the latching mode, when an alarm or shutdown condition is reached, the output remains in the alarm condition until it is reset by front panel pushbuttons, via the serial interface, or via the rear connector. In the non-latching mode, the output is automatically reset when the alarm condition no longer exists. Band deviation mode. Each relay may be set to operate in a band deviation mode, where an alarm is generated whenever the reading is a specified number of counts above or below the setpoint. In particular, band deviation is ideal to flag an out-of-tolerance condition. Hysteresis mode. Each relay may be set to operate in a hysteresis mode, where turn-on occurs at a specified amount above the setpoint and turn-off occurs at the same amount below the setpoint. Filtered or unfiltered input. Relay action may be derived from either the filtered or unfiltered DPM input signals. Using the unfiltered signal improves response time, which is typically 17 ms for a DPM with the solid state relay board. Fast response time is one of the major strengths of Micron DPMs, which can digitize analog data as often as 60 times per second. Using the filtered input reduces the chance of alarm triggering due to noise. Provisions for signal noise. A programmable time delay and reduction of relay chatter can be achieved in the DPM by selecting 1 to 128 readings in binary steps (17 ms to 2.1 s) prior to updating the output. Snubber circuitry is part of the contact relay board to prolong contact life. The relay response time of counters is controlled by a selectable gate time from 10 ms to 199.99 s. Relay Setup Setpoint values and operating modes can be entered via front panel pushbuttons or by computer via the serial interface. Security lockout modes of the front panel pushbuttons can be set to allow operators to view and change setpoint values, view but not changes setpoint values, or not view nor change setpoint values. The Micron Weight Meter and Batch Controller offer relay control modes beyond those of normal meter or counter operation. Electrical Connections Form C (SPDT) dual contact relays Relays can be connected to be normally open (OC) or normally closed ($0). Relay grounds are mutually isolated. Form A (SPST) quad contact relays Relays are normally open (NO). Each pair of relays shares an isolated ground. Form A (SPST) dual solid state relays Relays are normally open (NO). Relay grounds are mutually isolated. Form A (SPST) quad solid state relays Relays are normally open (NO). Each pair of relays shares an isolated ground. Setpoint Operating Modes Normal, Non-Latched Operation In this mode, the relay closes when the reading rises above the setpoint and opens when the reading falls below the setpoint. Relay ON/OFF control action is independently programmable for each of the two relays and can be reversed through a setup command. Latched Operation The relay stays actuated until reset externally. This mode can be used to shut down machinery or a process when an operating limit has been exceeded, or to maintain an alarm until acknowledged by an operator when the alarm condition has passed. Mixed Latched and Non-Latched Operation One of the relays can operate in a non-latched mode, for instance to turn off a heater when an operating temperature setpoint is reached. The other relay can operate as a latching fail-safe backup and turn off the entire process when a second, higher setpoint is reached, indicating a malfunction. Deviation Mode Operation A deviation limit (50 in this example) is set up around both sides of the setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and is often used for component testing. Wide Hysteresis Mode Operation In this example, a hysteresis limit of 600 is set below the setpoint. The relay closes when the reading reaches a lower limit (the setpoint less hysteresis) and opens when the reading reaches an upper limit (the setpoint). One application is automatic tank filling. A fill operation is automatically initiated when the tank level has reached a lower level and is terminated when the level has reached an upper level. Narrow Hysteresis Mode Operation Hysteresis can be used to minimize the number of ON/OFF control cycles around a setpoint, thereby increasing the life of motors, relays, etc. A very narrow hysteresis band (such as 5 counts) can also be used to minimize relay chatter around a setpoint due to electrical noise on the signal, or due to signal feedback caused by load switching. The hysteresis limit should exceed the noise amplitude. Specifications Operation Power Provided by meter Setup Front panel pushbuttons or via PC using RS232, RS485 or USB Input Filtering Setpoint compared to either filtered or unfiltered signal. Time Delay Unfiltered, or programmable delay from 1 to 128 readings Relay Operating Modes 1) Activate above or below setpoint 2) Latching or non-latching 3) Hysteresis or band deviation mode around each setpoint 4) Relays disabled Enable/Lockout Modes 1) Display and change setpoint via front panel pushbuttons. 2) Display setpoints via alarm pushbutton, but do not allow changes. 3) Disable pushbutton action for setpoints. Alarm Status Indication Type Two or four red LED indicators Lamp Lit When relay is energized Contact Relay Versions Form, Dual Relays Form C, single-pole, double-throw (SPDT) Form, Quad Relays Form A, single-pole, single-throw (SPST), normally open (NO) Current Rating 8A at 250 Vac or 24 Vdc Safety Rating 250V rms working, 2.3 kV rms per 1 min test Relay Grounds Grounds of dual relays are mutually isolated Grounds of quad relays are isolated in pairs Operate Time 7 ms (typical) from end of conversion Release Time 5 ms (typical) from end of conversion Solid State Relay Versions Form of Relays Form A, single-pole, single-throw (SPST), normally open (NO) Current Rating 120 mA at 140 Vac or 180 Vdc ON series resistance 18 ohms typical, 25 ohms max Isolation Type Optical Safety Rating 250V rms working, 2.3 kV rms per 1 min test Operate & Release Time 1 ms (typical) from end of conversion Environmental Operating temperature 0°C to 60°C Storage temperature. -40°C to 85°C Relative humidity 95% at 40°C, non-condensing Close
Relay types	2 Form C contact relays or 4 Form A contact relays (NO) 2 or 4 Form A, AC/DC solid state relays (NO)
Current tatings	8A at 250 Vac or 24 Vdc for contact relays 120 mA at 140 Vac or 180 Vdc for solid state relays
Output common	Isolated commons for dual relays or each pair of quad relays
Isolation	250V rms working, 2.3 kV rms per 1 min tes
Serial Communication I/O (optional) Serial I/O Module Specs. × Serial I/O Module Micron MM50 Meter Serial Communication Option Modules Serial Communication Option Boards Key Features Communication boards available for RS232, RS485, USB, Ethernet Usable in all 1/8 DIN size Laureate DPMs, counters, timers & remote displays All boards fully support Modbus and Laurel Custom ASCII protocols User-selectable baud rates to 19,200 Converter boards connect a USB or Ethernet line to RS485 bus with up to 31 meters Powered by instrument Isolated from meter and power grounds CE Mark RoHs Mark ETL Mark Made in the U.S.A. Description A serial communication option board allows a Micron digital panel meter, counter or timer to be interfaced to a PC for programming via Micron Windows-based Instrument Setup Software, or to output readings to a remote PC, PLC or other device with a serial communication port. The transmitted data may include the latest reading, peak value, valley value, alarm status, and setup information. The data can then be displayed, processed and data logged. The data can also be received by a Micron 6-digit remote display, which will display the serial data and also process the serial data to control relay outputs and generate a scaled, isolated 4-20 mA, 0-10V or -10V to +10V analog output. If the primary objective is to program a meter directly from a PC using Instrument Setup Software, an RS232 or USB interface board is recommended, depending on the available PC port. Once the meter has been programmed, the interface board can be removed if no longer needed. If the objective is to connect a network of meters to a PC, our USB 2.0-to-RS485 converter board can be used. That board can be connected to a PC via a USB port, and also act as the server for up to 31 meters on an RS485 bus via an RJ11 connector. The remote meters must be equipped with Micron RS485 interface board. That board features dual RJ11 connectors for RS485 daisy-chaining using commercial 6-wire RJ11 data cables, with no need for a hub. If the objective is to connect meters to an existing Modbus RS485 bus, either of two RS485 interface board can be selected. Our RS485 Modbus interface board uses RJ45 connectors as recommended by the Modbus standard, while our RS485 interface board uses RJ11 connectors, which are also used for Modbus. Both boards are fully compatible with the Modbus RTU and Modbus ASCII protocols, as are all other Micron serial interface boards. Both RS485 boards provide dual connectors (RJ485 or RJ11) for RS485 daisy-chaining using commercial 6-wire data cables with the appropriate connector (RJ485 or RJ11), with no need for a hub. If the objective is to connect a meter to an Ethernet LAN, our Ethernet interface board allows a meter to be connected to an available router port using a standard Ethernet cable. Our Node Manager software makes node discovery and setup exceptionally simple. If the objective is to connect a network of meters to an Ethernet LAN, our new Ethernet-to-RS485 converter board should be selected. That board can be connected to an Ethernet LAN utilizing a single Ethernet cable and also act as the server for up to 31 meters on an RS485 bus via an RJ11 connector. The remote meters must be equipped with Micron RS485 interface board. The Ethernet-to-RS485 converter board features dual RJ11 connectors for RS485 daisy-chaining using commercial 6-wire RJ11 data cables, with no need for a hub. Our new Node Manager software makes meter discovery and setup exceptionally simple. Three serial protocols are user-selectable: Modbus RTU, Modbus ASCII, and Micron ASCII. For more information, please see our Modbus Protocol Serial Communications Manual and our Serial Communications Manual. The Modbus protocol is an international standard and allows Microns to share the same RS485 data lines with non-Micron devices. It supports up to 247 digital addresses. Use of more than 31 Micron RS485 Modbus boards per line would require a repeater for impedance reasons. The Micron ASCII protocol is recommended if the only devices on the RS485 data line are Micron meters. It supports up to 31 digital addresses. Quick Selection Guide Interface Board Features & Compatibility Ethernet Board Ethernet Server RS232 Board Board USB Board USB Server RS485 Board RS485 Modbus Fits all 1/8 DIN Micron Instrument Setup software Modbus RTU & ASCII Conversion to Modbus TCP           Laurel ASCII protocol Networkable   Digitally addressable Single or duplex RS485       RS485 converter capability           Main Serial I/O Connector RJ45 RJ45 RJ11 USB USB RJ11 RJ45 Connectors for RS485 server   2 x RJ11     2 x RJ11     Specifications Electrical Specifications Electrical Safety & Isolation Isolation 250V rms working, 2.3 kV rms per 1 min test ESD Protection 15 kV per IEC 1000-4-2 EMI Immunity 10 V/m per IEC 1000-4-3 EFT Protection 2 kV per IEC 1000-4-4s Short Circuit Protection Continuous Selectable Protocols Modbus RTU, Modbus ASCII, Laurel ASCII. Protocol Specifications (implemented on meter main board) Modbus RTU Standards Compliance Modbus over Serial Line Specification V1.0 (2002) Data Formats (selectable) 1. No parity, 8 data bits, 2 stop bits 2. Odd parity, 8 data bits, 1 stop bit 3. Even parity, 8 data bits, 1 stop bit Applicable Interface Boards Ethernet, USB, RS232, RS485 Main Board Revision Level Level 5 or above Modbus ASCII Standards Compliance Modbus over Serial Line Specification V1.0 (2002) Data Formats (selectable) 1. No parity, 7 data bits, 2 stop bits 2. Odd parity, 7 data bits, 1 stop bit 3. Even parity, 7 data bits, 1 stop bit Applicable Interface Boards Ethernet, USB, RS232, RS485 Main Board Revision Level Level 5 or above Laurel ASCII Data Format No parity, 8 data bits, 1 stop bit Protocol Laurel Laurel ASCII Applicable Interface Boards Ethernet, USB, RS232, RS485 Main Board Revision Level Any Communication Option Module Overview Ethernet-to-RS485 converter board Provides an RJ45 connector to an Ethernet LAN plus an RJ11 connector to an RS485 bus. Supports Ethernet communications with the host meter or counter plus an additional 30 meters or counters on the RS485 bus. RS232 interface board Single RJ11 connector for point-to-point data communications to a PC RS232 COM port. Compatible with 4- or 6-wire data cables. RS485 interface boarddual RJ11 connectors Dual RJ11 connectors allow daisy-chaining without a hub. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection. RJ11 connectors allow use of commercial 6-wire data cables. RS485 interface board, dual RJ45 connectors Dual RJ45 connectors for daisy-chaining without a hub. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection. RJ45 connectors conform to the Modbus standard (but RJ11 connectors are more popular). USB 2.0 interface board Single USB Type-B receptacle for USB 2.0 I/O. Allows plug-and-pay connection of meter to a PC with a USB port. USB 2.0-to-RS485 converter board Includes a USB Type-B receptacle for USB 2.0 I/O plus an RJ11 connector for RS485. Allows meter to communicate with a PC via USB while also serving as a USB-to-RS485 converter and server for up a 31-device RS485 network. Close
Board selections	RS232, RS485 (dual RJ11 or RJ45 connectors), USB, Ethernet, USB-to-RS485 converter, Ethernet-to-RS485 converter
Protocols	Modbus RTU, Modbus ASCII, Modbus TCP (Ethernet), Custom ASCII
Data rates	300 to 19200 baud
Digital addresses	247 (Modbus), 31 (Custom ASCII),
Isolation	250V rms working, 2.3 kV rms per 1 min test
Signal Connections
Environmental
Operating temperature	0°C to 55°C
Storage temperature.	-40°C to 85°C
Relative humidity	95% at 40°C, non-condensing
Protection	NEMA-4X (IP-65) when panel mounted

Micron MM50 Series Power Modules

12-32 Vac or 10-48 Vdc power input board(left)
85-264 Vac or 90-300 Vdc power input (right)

Key Features

• Lightweight, high-frequency switching power supply design.
• 85-264 Vac or 90-300 Vdc power version
• 12-32 Vac or 10-48 Vdc power version
• Isolated 5, 10 or 24 Vdc transducer excitation output
• UL Recognized on-board fuse
• Three selectable isolated excitation outputs
• Certified to EN 61010-1 (CE mark) and RoHS
• ETL certified to UL 61010-1 and CSA C22.2#61010-1

Description

• High voltage AC or DC power. The standard Micron supply accepts power from 85-264 Vac, 47-63 Hz. This allows the same meter to operate worldwide without modification. The supply also accepts 90 to 300 Vdc (high voltage DC operation not ETL approved).
• Low voltage AC or DC power. An optional low voltage supply operates from 10 to 48 Vdc or 12 to 30 Vac, 47-63 Hz. This supply allows the Micron to be powered from batteries or from 28 Vac, 400 Hz aircraft power (400 Hz operation not ETL approved).

Isolated Excitation Output

Each power supply provides three jumper-selectable, isolated excitation outputs: 5 Vdc at 100 mA, 10 Vdc at 120 mA, or 24 Vdc at 50 mA. These outputs can be used to power external sensors, transmitters and up to four 350 ohm load cells in parallel, thereby avoiding the need for an expensive external supply. When powering a load cell or potentiometer, a ratiometric operating mode can be selected, where the meter monitors the excitation supply and removes the effects of voltage variation.

In addition to the isolated excitation output, regulated 5 Vdc at up to 50 mA is brought out and can be used to power external logic.

Wiring of Excitation Output

4-Wire, 4-20mA Transmitter Wiring

2-Wire, 4-20mA Transmitter Wiring

• With four-wire transmitters, two wires are used to apply 10 or 24 Vdc, and two separate wires are used to sense the transmitter's 4-20 mA output.
• With two-wire transmitters, the same two wires are used to power the transmitter and carry the 4-20 mA output, which is made to flow across an internal 10 ohm resistor between pins 3 and 4.

OPERATING POWER
Module PS1 Module PS2 Frequency Power Consumption	85-264 Vac or 90-300 Vdc 12-32 Vac or 10-48 Vdc DC and 47-63 Hz 5.3 W max
PROTECTION
Module PS1 Module PS2	Module PS2 On-board fuse rated 0.5A, 277 Vac, UL Recognized On-board fuse rated 2.5A at 250 Vac or 63 Vdc, UL Recognized
EXCITATION POWER SUPPLY
Selectable Outputs	5 Vdc ± 5%, 100 mA 10 Vdc ± 5%, 120 mA 24 Vdc ± 5%, 50 mA
Ripple Isolation to Power Gound Isolation to Meter Ground	50 mVp-p max 250V rms working, 2.3 kV rms per 1 min test 50 Vp
PIN ASSIGNMENT (POWER & DIGITAL CONTROLS)

Micron MM50 Meter Dual or Quad Relay Option Modules

Dual 8A Contact Relays

Quad 8A Contact Relays

Dual 120mA Solid State Relays

Quad 120mA Solid State Relays

CE Mark

RoHs Mark

ETL Mark

Made in the U.S.A.

Electrical Connections

Form C (SPDT) dual contact relays Relays can be connected to be normally open (OC) or normally closed ($0). Relay grounds are mutually isolated.

Form A (SPST) quad contact relays Relays are normally open (NO). Each pair of relays shares an isolated ground.

Form A (SPST) dual solid state relays Relays are normally open (NO). Relay grounds are mutually isolated.

Form A (SPST) quad solid state relays Relays are normally open (NO). Each pair of relays shares an isolated ground.

Setpoint Operating Modes

Normal, Non-Latched Operation In this mode, the relay closes when the reading rises above the setpoint and opens when the reading falls below the setpoint. Relay ON/OFF control action is independently programmable for each of the two relays and can be reversed through a setup command.

Latched Operation The relay stays actuated until reset externally. This mode can be used to shut down machinery or a process when an operating limit has been exceeded, or to maintain an alarm until acknowledged by an operator when the alarm condition has passed.

Mixed Latched and Non-Latched Operation One of the relays can operate in a non-latched mode, for instance to turn off a heater when an operating temperature setpoint is reached. The other relay can operate as a latching fail-safe backup and turn off the entire process when a second, higher setpoint is reached, indicating a malfunction.

Deviation Mode Operation A deviation limit (50 in this example) is set up around both sides of the setpoint. The relay closes (or opens) when the reading falls within the deviation band, and opens (or closes) when the reading falls outside of this band. This mode sets up a passband around the setpoint and is often used for component testing.

Wide Hysteresis Mode Operation In this example, a hysteresis limit of 600 is set below the setpoint. The relay closes when the reading reaches a lower limit (the setpoint less hysteresis) and opens when the reading reaches an upper limit (the setpoint). One application is automatic tank filling. A fill operation is automatically initiated when the tank level has reached a lower level and is terminated when the level has reached an upper level.

Narrow Hysteresis Mode Operation Hysteresis can be used to minimize the number of ON/OFF control cycles around a setpoint, thereby increasing the life of motors, relays, etc. A very narrow hysteresis band (such as 5 counts) can also be used to minimize relay chatter around a setpoint due to electrical noise on the signal, or due to signal feedback caused by load switching. The hysteresis limit should exceed the noise amplitude.

Micron MM50 Meter 16-Bit Analog Output Option Module

16-Bit Analog Option Board

Key Features

• 16-bit resolution (1 part in 65,536 or 0.0015% of full scale)
• 4-20 mA, 0-20 mA, 0-10V, or bipolar -10 to +10V analog output
• Analog output linearized to reading
• Analog output isolated to 250 Vac
• ±0.02% full scale accuracy
• Scale and offset via meter front panel, RS232, RS485 or USB
• Certified to EN 61010-1 (CE mark) and RoHS
• Output derived from filtered or unfiltered signal input
• 12V compliance at 20 mA

CE Mark

RoHs Mark

ETL Mark

Made in the U.S.A.

Description

A 16-bit analog output option board can turn a Micron 1/8 DIN digital panel meter, counter, timer or remote display into a superb, isolated, linearized transmitter or signal conditioner with exceptional accuracy and high-speed response. The analog output for thermocouples, RTDs and custom curves is linearized to the displayed reading.

The analog output can be selected as 4-20 mA, 0-20 mA, unipolar 0-10V, or bipolar -10V to +10V with a 20V span and 0V at mid-range. If a voltage output is selected, output pins 1 and 2 may be reversed to provide reversed polarity.

A 16-bit D-to-A converter provides 0.0015% full-scale resolution and ±0.02% full-scale accuracy. The update rate for meters is a fast 60/sec for 60 Hz power or 50/sec at 50 Hz power. The analog output can track the unfiltered signal for fastest response, or a digitally filtered signal for best noise rejection.

Isolation from power and signal is provided by a separate power supply in the meter. This supply can drive 20 mA of current into loads up to 600 ohms for 12V compliance. Isolation to signal ground and power ground eliminates problems caused by ground loops.

Scaling of the analog output can be via the meter's front panel pushbuttons or a serial digital interface using Instrument Setup software. The displayed readings to produce the low and high analog outputs can be set to any value from -99999 to +99999 for DPMs or from -999999 to +999999 for counters and timers. Depending on your selected output range, simply set the meter reading for low analog output (4 mA, 0 mA, 0V or -10V) and for high analog output (20 mA or 10V).

The bipolar -10V to +10V analog output can provide a negative signal for a negative deviation from a setpoint, and a positive signal for a positive deviation. It can also be used for proportional control around a setpoint. For example, if proportional control is desired around 170°C with a ±10°C span, set the -10V output to 160°C and the +10V output to 180°C. The control signal will be 0V at 170°C.

Micron DIN rail transmitters come standard with a 4-20 mA, 0-20 mA, 0-10V, or bipolar -10 to +10V analog output with 16-bit resolution.

Specifications

Electrical
Power source		Provided by meter
Signal source		Filtered or unfiltered digitized signal
Output linearization		Linearized to reading
Output Levels (selectable)		4-20 mA, 0-20 mA, 0-10V, -10 to 10V
Compliance at 20 mA		12V ( 600 Ω max load )
Compliance at 10 V		2 mA ( 5 kΩ min load)
Isolation		250V rms working, 2.3 kV rms per 1 min test
Output resolution		16 bits (0.0015% of full scale)
Output nonlinearity		< 0.01% of full scale
Accuracy		< 0.02% of full scale
Output update rate, DPMs		50 or 60/sec (output may be digitally filtered)
Output update rate, counter rate meter		Gate time + 30 ms + 0-2 periods
Scaling
Zero output & full-scale output, DPMs		-99,999 to +99,999 counts
Zero output & full-scale output, counters		-999,999 to +999,999 counts
Minimum span		150 counts
J4 Pin Assignments
Unipolar Connections		Bipolar Connections
4-20 mA or 0-20 mA output 1		Reference or Return 1
0-10V output 2		-10V to +10V Output 2
Isolated ground 3		N/C 3

Micron MM50 Meter Serial Communication Option Modules

Serial Communication Option Boards

Key Features

• Communication boards available for RS232, RS485, USB, Ethernet
• Usable in all 1/8 DIN size Laureate DPMs, counters, timers & remote displays
• All boards fully support Modbus and Laurel Custom ASCII protocols
• User-selectable baud rates to 19,200
• Converter boards connect a USB or Ethernet line to RS485 bus with up to 31 meters
• Powered by instrument
• Isolated from meter and power grounds

CE Mark

RoHs Mark

ETL Mark

Made in the U.S.A.

Description

A serial communication option board allows a Micron digital panel meter, counter or timer to be interfaced to a PC for programming via Micron Windows-based Instrument Setup Software, or to output readings to a remote PC, PLC or other device with a serial communication port. The transmitted data may include the latest reading, peak value, valley value, alarm status, and setup information. The data can then be displayed, processed and data logged. The data can also be received by a Micron 6-digit remote display, which will display the serial data and also process the serial data to control relay outputs and generate a scaled, isolated 4-20 mA, 0-10V or -10V to +10V analog output.

If the primary objective is to program a meter directly from a PC using Instrument Setup Software, an RS232 or USB interface board is recommended, depending on the available PC port. Once the meter has been programmed, the interface board can be removed if no longer needed.

If the objective is to connect a network of meters to a PC, our USB 2.0-to-RS485 converter board can be used. That board can be connected to a PC via a USB port, and also act as the server for up to 31 meters on an RS485 bus via an RJ11 connector. The remote meters must be equipped with Micron RS485 interface board. That board features dual RJ11 connectors for RS485 daisy-chaining using commercial 6-wire RJ11 data cables, with no need for a hub.

If the objective is to connect meters to an existing Modbus RS485 bus, either of two RS485 interface board can be selected. Our RS485 Modbus interface board uses RJ45 connectors as recommended by the Modbus standard, while our RS485 interface board uses RJ11 connectors, which are also used for Modbus. Both boards are fully compatible with the Modbus RTU and Modbus ASCII protocols, as are all other Micron serial interface boards. Both RS485 boards provide dual connectors (RJ485 or RJ11) for RS485 daisy-chaining using commercial 6-wire data cables with the appropriate connector (RJ485 or RJ11), with no need for a hub.

If the objective is to connect a meter to an Ethernet LAN, our Ethernet interface board allows a meter to be connected to an available router port using a standard Ethernet cable. Our Node Manager software makes node discovery and setup exceptionally simple.

If the objective is to connect a network of meters to an Ethernet LAN, our new Ethernet-to-RS485 converter board should be selected. That board can be connected to an Ethernet LAN utilizing a single Ethernet cable and also act as the server for up to 31 meters on an RS485 bus via an RJ11 connector. The remote meters must be equipped with Micron RS485 interface board. The Ethernet-to-RS485 converter board features dual RJ11 connectors for RS485 daisy-chaining using commercial 6-wire RJ11 data cables, with no need for a hub. Our new Node Manager software makes meter discovery and setup exceptionally simple.

Three serial protocols are user-selectable: Modbus RTU, Modbus ASCII, and Micron ASCII. For more information, please see our Modbus Protocol Serial Communications Manual and our Serial Communications Manual.

• The Modbus protocol is an international standard and allows Microns to share the same RS485 data lines with non-Micron devices. It supports up to 247 digital addresses. Use of more than 31 Micron RS485 Modbus boards per line would require a repeater for impedance reasons.
• The Micron ASCII protocol is recommended if the only devices on the RS485 data line are Micron meters. It supports up to 31 digital addresses.

Quick Selection Guide

Interface Board Features & Compatibility	Ethernet Board	Ethernet Server	RS232 Board Board	USB Board	USB Server	RS485 Board	RS485 Modbus
Fits all 1/8 DIN Micron
Instrument Setup software
Modbus RTU & ASCII
Conversion to Modbus TCP
Laurel ASCII protocol
Networkable
Digitally addressable
Single or duplex RS485
RS485 converter capability
Main Serial I/O Connector	RJ45	RJ45	RJ11	USB	USB	RJ11	RJ45
Connectors for RS485 server		2 x RJ11			2 x RJ11

Specifications

Electrical Specifications

Communication Option Module Overview

Ethernet-to-RS485 converter board Provides an RJ45 connector to an Ethernet LAN plus an RJ11 connector to an RS485 bus. Supports Ethernet communications with the host meter or counter plus an additional 30 meters or counters on the RS485 bus.

RS232 interface board Single RJ11 connector for point-to-point data communications to a PC RS232 COM port. Compatible with 4- or 6-wire data cables.

RS485 interface boarddual RJ11 connectors Dual RJ11 connectors allow daisy-chaining without a hub. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection. RJ11 connectors allow use of commercial 6-wire data cables.

RS485 interface board, dual RJ45 connectors Dual RJ45 connectors for daisy-chaining without a hub. Jumper selectable 2-wire (half duplex) or 4-wire (full duplex) connection. RJ45 connectors conform to the Modbus standard (but RJ11 connectors are more popular).

USB 2.0 interface board Single USB Type-B receptacle for USB 2.0 I/O. Allows plug-and-pay connection of meter to a PC with a USB port.

USB 2.0-to-RS485 converter board Includes a USB Type-B receptacle for USB 2.0 I/O plus an RJ11 connector for RS485. Allows meter to communicate with a PC via USB while also serving as a USB-to-RS485 converter and server for up a 31-device RS485 network.

Micron MM50 Series Signal Conditioner Modules

Four signal conditioner boards are selectable for DPMs:

• DC (volts, amps, mV, mA, process, potentiometric ratio).
• AC True RMS (AC volts, mV, amps, mA).
• Thermocouple (Types J, K, T, E, N, R, S)
• RTD (Pt 100, Ni 120, Cu 10) and Ohms (2 Ω to 2 MΩ ranges)
• Load cell (load cell, strain gauge, scale meter, microvolts).

Three input boards are selectable for counters:

• Frequency, period, rate (dual pulse inut channels A & B, 0.005 Hz to 1 MHz)
• Digital stopwatch (for single or accumulated events)
• Time interval meter (for average of periodic events)
• Power factor & phase angle meter (for AC signals)
• Duty cycle meter (or or off period as a percentage of total period)
• Up / down totalizer (with dual channels A & B, with external inputs for external control)
• Ratio, draw, channels A+B, A-B, AxB, A/B, A/B-1 (arithmetic operations on dual pulse input channels A & B)
• Batch controller (to control recurring fill operations from pulse inputs)
• Voltage-to-frequency converter (rate, total, batch control from analog inputs)
• Quadrature meter / controller (position or rate from encoder signals)

If you have additional Question on the MM50 Meters, send us a message via our contact page.

Micron MM50 1/8 DIN Case

For Micron Digital Panel Meters, Counters, Timers & Remote Displays

Dimensions

Micron MM50 Digital Panel Meter
for True RMS AC Voltage and Current

Data Sheet - AC Voltage & Current

Manual - MM50 Series 2 Digital Panel Meter