Dataforth Corporation, Tucson, Arizona announces the introduction of its new DSCL series of external powered and loop powered isolators. These isolators provide a simple low-cost solution for providing protection for analog voltage and current signals. They are designed to protect valuable measurement and control signals as well as connected equipment from the dangerous and degrading effects of noise, transient power surges, internal ground loops, and other hazards present in industrial environments.

Five basic model types, the DSCL20, DSCL21, DSCL22, DSCL23, DSCL24, and DSCL25 make up the family of 20 isolators. All provide input-to-output transformer isolation ranging from 500Vrms up to 4000Vrms. Some are loop powered, deriving their power from the input signal, while others accept external universal power of either 24 to 60V AC/DC or 85 to 230V AC/DC. Accuracy for the loop powered models is better than ±0.1%, and the external powered models are better than ±0.2%. Packaging options are many; including component style for printed circuit board mounting, small profile 12.5mm and 17.5mm wide DIN rail packages, and panel mount packages. Depending on the model, they accept a wide range of voltage or current inputs and provide high-level analog outputs in either fixed-gain or hardware programmable settings. Operating temperature range is from -25°C to +65°C.

Each DSCL20 and DSCL21 provides a single channel of 500Vrms-transformer isolation for analog signals in the range of 0(4) to 20mA. They operate passively, deriving their power from the input signal. No external power supply is required. The DSCL20 is packaged in a “component” style package ideal for printed circuit board mounting. It only measures 1.6 by 0.8 by 0.4 inches (41mm by 21mm by 10.3mm), and is available in both straight and right angle pins. A socket and hold-down accessory which can be soldered into a printed circuit board, the DSCX-01, allows plugging and unplugging the straight pin model for OEM design applications. The DSCL21 is a DIN rail mount version of the DSCL20 component module. It is very compact for high density mounting, measuring only 0.5 inches (12.5mm) wide and 2.95 inches (75mm) tall.

The DSCL22 and DSCL23 are similar in function; both provide loop powered isolation for 0(4) to 20mA analog signals deriving power from the input signal, and both are available in multi-channel versions. No external power supply is required. The DSCL23 differs slightly from the DSCL22 since it can feed isolated DC power from it’s output side to a field transmitter connected to it’s input side.

The DSCL22 provides 4000Vrms-transformer isolation in the single channel version. Two and three channel models are available which provide 2300Vrms-transformer isolation. All have an input range of 0(4) to 20mA and output ranges of 0(4) to 20mA or 0(2) to 10V.

Each DSCL23 provides 2300Vrms-transformer isolation in either the one or two channel versions. The DSCL23 is unique in the industry since DC power on the output side is isolated and is provided to a two-wire transmitter connected to the input side. The returned 4 to 20mA input signal from the transmitter is also isolated and passed back to the output side. Input and output ranges are fixed at 4 to 20mA. The DC power supply can vary between 12 and 30VDC, and a minimum of 21.3VDC is supplied to the input connected transmitter when the power supply is 24VDC. Packaging for both the DSCL22 and DSCL23 is a narrow DIN rail case measuring only 0.69 inches (17.5mm) wide for high density mounting. Mounting tabs can be extended from the case for panel mount applications.

The DSCL24 provides 2300Vrms I/O isolation and 3700Vrms power supply to I/O isolation for all models. Two model versions are offered that accept universal power of either 24 to 60V AC/DC or 85 to 230V AC/DC, with the AC usage accepting 45 to 400Hz power. The single channel model has four user configurable jumpers that provide 36 different I/O settings. A unique snap-in tool allows quick extraction of the module’s circuit board to permit the user to reposition the jumpers for different I/O requirements. The multi-channel DSCL24 is factory configurable for up to 252 different configurations of process current or voltage inputs and outputs. Packaging is a narrow DIN rail case measuring only 0.69 inches (17.5mm) wide for high density mounting. Mounting tabs can be extended from the case for panel mount applications.

For additional information and pricing, call 800-444-7644 toll-free, or e-mail at

Original release: January 2000