4-20 mA Current Output Transmitter
& Dual Pulse Input Totalizer

Standard Features

• Isolated 4-20 mA or 0-10V transmitter outputs, selectable
• Two independent, scalable totals for Channels A & B
• Pulse input rates to 1 MHz
• Inputs from NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up to 250 Vac.
• Internal conversion of input to six-digit reading:
  - Digital span adjust from 0 to ±999,999
  - Digital zero adjust from -999,999 to +999,999
• Up counting from zero to preset value using positive scale factor
• Down counting from preset to zero using negative scale factor
• Output resolution:  0.0015% of span (16 bits)
• Output accuracy: ±0.02% of span
• DIN rail mount package only 22.5 mm thick
• Detachable screw clamp plug connectors
• Easy setup with PC-based Instrument Setup Software
• 5V, 10V or 24V dc sensor excitation output, isolated
• Dual solid state relays for alarm or control, isolated
• RS232 or RS485 serial communications, isolated
• Universal AC power, 85-264 Vac
• Priced Reasonably (basic totalizer transmitter)
  Options:
• Extended Main Board for Channel A total and Channel B rate simultaneously,
  Up/down counting on Channel A, using Channel B to control count direction,
  Counting on Channel A, using Channel B to inhibit counting,
  Arithmetic functions A+B, A-B, AxB, A/B, A/B-1 (draw).
• Low voltage power, 10-48 Vdc or 12-30 Vac

Description

The Micron 4-20 mA output, pulse input totalizer transmitter accepts two independently scalable input channels from a wide range of pulse sources, such as NPN or PNP proximity switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC voltages to 250 Vac. Input pulse rates can be as high as 1 MHz.

• With a Standard Main Board, the transmitter output can be scaled to engineering units, for example to transmit totalized flow in gallons from a flow meter output. Square root extraction is standard.
  
• With an Extended Main Board, the transmitter output can track rate or totalized rate (such as gallons) whether the transducer output is linear, requires square root extraction, or requires custom curve linearization. The latter can be provided by a curvilinear spline fit with up to 180 data points. The transmitter can also count up to a preset total or down from a preset total to zero. Such applications typically make use of optional dual solid state relays, which are available as options. External reset of totals is via a special three-position screw terminal connector. The two input channels A & B can also be combined arithmetically to provide an analog transmitter output that tracks A+B (e.g., sum of two flows), A-B (e.g., difference of two flows), AxB (e.g., horsepower as product of force and RPM), A/B (ratio of two flow), or A/B-1 (draw or relative elongation of material between rollers).

The dual-channel signal conditioner used for pulse detection accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS logic, magnetic pickups, contact closures, and other signals from 12 mV to 250 Vac. Jumper selections provide optimum operation for different sensor types and noise conditions. A built-in 5V, 10V or 24V dc excitation supply can power proximity switches and other sensors, and eliminate the need for an external power supply.

Standard features of Micron transmitters include:

• Analog transmitter output, 16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
• Serial communications, isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Micron ASCII protocol.
• Dual solid state relays for control or alarm, isolated. Rated 120 mA at 130 Vac or 170 Vdc.
• Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
• Universal AC power supply for 85-264 Vac.

Easy Transmitter programming is via Micron's Instrument Setup Software, which runs on a PC under MS Windows. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Micron (P/N CBL04).

Up/down totalizing is provided by a mode of the Extended totalizing transmitter where pulses are either added or subtracted on Channel A based on a direction input on Channel B. The unit can also be programmed so that counting by Channel A is inhibited by an input on Channel B.

A+B, A-B, A/B and AxB arithmetic functions are available with the Extended totalizing transmitter. A+B can sum two totals, while A-B subtracts the outflow total from inflow total. A/B ratio applied to two totals helps assure the proper mixing of components.

A single Micron dual-channel totalizing transmitter will handle two repetitive fill operations by counting from zero up to a preset, or down from a preset to zero. The dual relay option is required.

An easy way to measure the ON time of machines is to count AC line cycles and scale the total to hours. To display machine utilization or duty cycle in percent, use the Extended totalizing transmitter. Connect Channel A to switched AC and Channel B to the AC line, and apply a 100 multiplier to the A/B ratio.

The Extended version of the Micron dual channel totalizing transmitter can transmit scaled rate or total for the same channel at the push of a button, and alarm both the rate and total. The Extended version can also do curve linearization, thereby extending the working range and accuracy of flow transducers.