Originally published on GMI blog by GM International| May 22, 2019
The associated apparatus to interface intrinsically safe devices are vital in hazardous environments: these are indeed the barriers between the equipment on site, i.e. the hazardous area, and those in the control room. These segregate non-intrinsically safe circuits from intrinsically safe ones, characterized by clearly identified and limited electrical parameters.
Galvanic isolators, such as the D5212Q from GM International, are part of this special category of equipment. This is an analog input module offering a fully floating DC power supply for conventional 4-20 mA or 0-20 mA two-wire transmitters located in hazardous areas. The D5212Q galvanic isolator, part of the D5000 series, repeats the signal in an isolated circuit in a safe area, also in functional safety applications in high risk industrial environments. As with all other barriers of the D5000 series, the input signal can come from a hazardous area classified as Zone 0 or Division 1, while the installation of the module will be in Zone 2 or Division 2, mounted on standard DIN-Rail or on termination boards. This module ensures isolation between input, output and power supply, while maintaining full flexibility based on the required combination of inputs and outputs. Any number of outputs can be independently connected to each input, and the output functions can be configured as sum or subtraction of two channels, or even minimum or maximum signal selector between two channels. A fully configurable alarm output is also provided.
Highlights of the D5212Q module
As previously explained, the key feature of the D5212Q module compared to traditional analog input modules is its configurability. This is completely software-based, without the need for manual operations inside the device, using a computer. Through the GM SWC5090 software, available for download from the website, the configurable values of this module are manifold: at the input the fault thresholds of each signal can be completely modified, while at the output the signals can be scaled, the value of the fault current can be modified, the source of the signal from the input channels and the related operations can be set. Likewise, the alarm contact can be freely managed. All these values can also be written and monitored via the RS485 Modbus protocol.
To round off the overview, the D5212Q module does not sacrifice the other features common to the entire D5000 series: it deals with 4 passive analogue channels in just 22 mm thickness, also offering the possibility of alternately connecting two active transmitters to the first two channels. The front panel allows a glance at the operation of the module, with LEDs indicating the presence of power, the status of each channel and the alarm contact. The use of reliable components allows the module to be used at temperatures between -40°C and +70°C, allowing complete installation flexibility. The safety approvals received by third parties make it a unit suitable in any industrial environment, from explosion-hazardous areas to functional safety applications up to the maritime sector, proving GM International's equal commitment to development of products which can be simple, but ready-for-use, and complex, yet incredibly flexible.