New Products from Laurel Electronics
As of 26 Feb 2010

Model QLS Quad Output Loop Splitter / Retransmitter sources up to four (4) independently adjustable 4-20 mA outputs from a single input, which can be 4-20 mA, 1-5V, 0-5V or 0-10V, as selected by jumpers. The outputs can share a common ground. The input and outputs are mutually isolated to ±10V by means of active circuitry to accommodate differences in local grounds with normal industrial grounding practices. If any device in an output loop is removed from a loop or fails, or if a wiring fault occurs, the other loops continue to operate properly. Each loop only drives a single load, avoiding compliance problems. Now shipping.

Model QLS overcomes problems associated with the common industrial wiring practice where the same 4-20 mA signal from a transmitter is sent to multiple devices in series. In such a circuit, the devices in the loop cannot share a common ground, but must be electrically floating, which is often not possible. When any device in the loop is removed, fails or if a wiring fault occurs, all other devices in the loop loose their 4-20 mA signal. In a single loop, the transmitter voltage compliance limit may be exceeded, since the voltage drops across loads in series are additive. Also, the 4-20 mA signal to each load cannot be individually adjusted for calibration purposes.

The LTS6 Serial Input to Analog Output Converter accepts RS-232 or RS-485 serial data with the Modbus or Laurel ASCII protocol, and converts it to an isolated, scalable 4-20 mA, 0-20 mA or 0-10V analog output signal. The unit fits on a 35 mm DIN rail and is only 22.5 mm (0.89") thick. It is normally powered by AC (85-264 Vac), but can optionally be powered by low voltage AC or DC. All electrical connections are via detachable screw-clamp plugs.

The Analog transmitter output is exceptionally accurate. 16-bit resolution provides an ultra-fine resolution of 0.0015% and accuracy better than 0.02% of output span. Output isolation from signal, power and serial communication grounds is provided by a separate on-board transmitter power supply, thereby eliminating potential problems caused by ground loops.

Dual solid state relays for control or alarm are standard. The relay outputs are i isolated isolated and are rated for a 120 mA current at 130 Vac or 170 Vdc.

New True RMS Meter is accurate to 0.1%, responds in one
50/60 Hz line cycle.

Most AC meters are slow, with multi-second settling times, are not all that accurate, especially on the low end of their ranges, and are limited in their ability to process distorted waveforms and higher frequencies. The newest version of the Laureate True RMS Meter, now shipping, blows all competition away with no price increase. This 5-digit meter represents a quantum improvement over the successful previous version of Laurel's AC RMS meter. Features include:

• Ultra-fast, true RMS measurements at rates up to 60 Hz, or down to 17 ms between measurements. This allows AC power line problems to be detected and acted upon using relays at the end of every AC line cycle. Fast meter response can avoid expensive equipment damage in case of an AC power problem. Fast response also allows peak and valley capture of transients (standard), and is also great for datalogging.
   
• High accuracy with error less than 0.1% of full scale for amplitudes from 100% of full scale all way down to 0%. Accuracy is maintained for frequencies from 10 Hz to 10 kHz and a crest factor up to 3.0 at full scale, which accommodates very distorted waveforms.
   
• AC or DC coupling. DC coupling was not available in Laurel's previous RMS meter.

Laurel's isolated 12-bit analog output option has long been  popular for Laureate digital panel meters and counters, since it effectively turns these instruments into isolated, linearized transmitters. The new version of this board, now shipping, offer 16-bit resolution, or a 16 times smaller step size, plus a ±10V bipolar output. Features include:

• 16-bit resolution (1 part in 65,536 or 0.0015% of full scale)
• Accuracy with error less than 0.02% of full scale
• Output selectable as 4-20 mA, 0-20 mA, 0-10V, or -10V to +10V
• Output linearized to reading
• Output isolated to 250 Vac
• Fast update rate to 60 Hz (every 17 ms)
• Output digitally filtered or unfiltered

Laurel has been offering three serial communication options for its meters and counters: 1) an RS232 interface board for direct connection to a PC, 2) an RS485 board with RJ11 connectors for multipoint communications using the simple Laurel ASCII protocol, and 3) a Modbus RS485 board with RJ45 connectors for multipoint communications using the industry-standard Modbus protocol. Two versions of a USB interface board are now shipping:

• USB 2.0 interface board with a single Type-B connector for a standard USB cable. Allows plug-and-pay connection of a meter or counter to the latest generation of ultra-compact laptop computer which have USB ports but no RS232 com port. Ideal for programming instruments with Laurel's free Instrument Setup Software. The board can be removed once the instrument has been programmed.

• USB 2.0 to RS485 converter board. Includes a USB Type-B connector for USB 2.0 communications plus an RJ11 connector for RS485. Allows a meter or counter to communicate with a PC via a USB cable while also serving as the USB-to-RS485 converter and hub for connection of the PC to an RS485 network with multiple meters and counters. The simple Laurel ASCII protocol and industry-standard Modbus protocol are fully supported.

Upgraded line of DIN Rail Transmitters improves resolution
16-fold, makes former options standard.

Laurel has upgraded its entire line of DIN rail transmitters from 12-bit to 16-bit analog output resolution and has made formerly optional features standard. These new transmitters are now shipping. Standard features include:

• Isolated 4-20 mA, 0-20 mA or 0-10V analog output with 16-bit resolution
• Isolated RS232 or RS485 serial communications, half or full duplex
• Modbus RTU, Modbus ASCII or simple Laurel ASCII serial protocol
• Dual solid state relays for alarm or control
• Ability to accept the same signal conditioners as Laureate meters & counters

The model numbers of the new transmitters all start with the letter L. LTA series transmitters, where the A stands for "Analog output," and LTM series transmitters, where the M stands "Mobus serial output," are now really the same series. We kept the series model numbers different for continuity with the previous TA and TM series.

Laurel transmitters are available for most types of industrial signals and accept the same signal conditioner boards as Laurel's meters and counters. This includes analog signals such as DC, AC, process, load cell and temperature, plus pulse type signals such as contact closures, TTL outputs, or the output of turbine flow meters and quadrature encoders. The transmitters are set up using the same Instrument Setup Software as Laureate digital panel meters and counters, and offer the same rich set of programmable features, such as output scaling and selectable digital filtering modes.

The TS6 serial-to-analog converter is a unique transmitter without a signal conditioner. It meets the demand of users who need to convert a serial communications signal (RS232, RS485, Modbus R485) to an isolated analog signal.

Four-relay output boards will join the existing two-relay output boards and start shipping in at the end of August 2009 for the entire line of 1/8 DIN Laureate digital panel meters, counters, timers and remote displays. The price premium for the additional two relays is only $20. There are now four Laureate relay options:

1)  Two contact relays
2)  Two solid state relays
3)  Four contact relays
4)  Four solid state relays

The dual contact relays are rated for 8A at 250 Vac or 24 Vdc. The solid state relays can switch AC or DC and are rated for 130 mA at 140 Vac or 180 Vdc. Solid state relays do not experience contact wear. They are recommended for frequent operation or switching very low currents. Each of the relays can be programmed for maximum flexibility for alarm or control:

1)  To have its own setpoint
2)  To be activated above or below the setpoint
3)  To be latching or non-latching
4)  To operate in the hysteresis or band deviation mode around the setpoint

Laureate temperature meters have been able to accept two types of 100 ohm platinum (Pt 100) resistance temperature detectors RTD). An upgraded RTD board is now shipping, which is also capable of handling 10 ohm Copper RTDs and 120 ohm Nickel RTDs. The new board is factory calibrated and linearized for the following four RTD types:

1)  100 ohm platinum RTD with DIN alpha of 0.00385
2)  100 ohm platinum RTD with ANSI alpha of 0.003902
3)  10 ohm Copper RTD with alpha of 0.00427
4)  120 ohm Nickel RTD with alpha of 0.00672

RTDs have a narrower temperature range than thermocouples, but they are more linear and much more accurate. They are ideal for Laureate meters, which have an A/D conversion accuracy of 0.01% of full scale. By using adaptive digital noise filtering, Laureate RTD meters can provide stable temperature readings with a resolution of 0.01°C or 0.01°F, while responding rapidly to actual changes in signal.

Laureate RTD meters allow 2, 3 or 4-wire hookup. With 3 or 4-wire hookup, the meter will automatically remove effects caused by lead wire resistance in long cable runs.

Ohms resistance meter added to Laureate DPM series

In response to market demand, Laurel has added resistance measurement capability to its Laureate line of meters. The signal conditioner board, which is the same as the enhanced RTD board, is now shipping. There are five resistance ranges:

1)  20 ohms with 1 milliohm resolution
2)  200 ohms with 10 milliohm resolution
3)  2,000 ohms with 100 milliohm resolution
4)  20,000 ohms with 1 ohm resolution
5)  200,000 ohms with 10 ohm resolution

One of the applications for resistance panel meters is to measure contact resistance in production environments. This is where the extremely low 1 milliohm resolution shines. As for the Laureate RTD meter, 3- and 4-wire hookup allows the meter to eliminate the effect of lead wires, whose resistance would otherwise be included in resistance measurement. A special 2 megohm range is available as a factory special.

A single isolated analog output board has long been available as an option for Laureate 1/8 DIN DPMs, counters, timers & remote displays, effectively turning these into isolated transmitters. Four output levels are user selectable, all with 16-bit resolution: 4-20 mA, 0-20 mA, 0-10V, or -10V to +10V.

A second isolated analog output board, now shipping, provides two individually configurable and scalable analog outputs for Laureate counters, timers and remote displays. While these instruments can only display one item at a time, they are able to track multiples items simultaneously. For example, the Laureate Extended ratemeter and totalizer can simultaneously track rate (such as flow rate) and total (such as fluid volume), which can each be displayed at the press of a button. With the new dual analog channel output board, these can now each have an associated 4-20 mA transmitter output.

We are actively working on two Ethernet communication boards, which will join our existing RS232, RS485, Modbus RS485, USB, and USB-to-RS485 converter boards. Expect first Ethernet board shipments in Spring 2010. There will be two versions:

• Ethernet board with a single RJ45 connector for connection to a Cat-5 Ethernet cable at 10 MBits/sec. 

• Ethernet-to-RS485 converter board (shown above). Includes an RJ45 connector for Ethernet plus an RJ11 connector for RS485. Allows a meter or counter to communicate with a PC via an Ethernet cable while also serving as an Ethernet-to-RS485 converter and hub for connection of the PC to an RS485 network with multiple meters and counters. The simple Laurel ASCII protocol and industry-standard Modbus protocol will be fully supported.