D2000M series Intrinsically Safe Multiplexing System consists of one to four Analog-Temperature Multiplexer units model D2010M, up to twelve Expander units model D2011M, or up to four Digital Multiplexer units model D2030M, mounted in Hazardous Area/Hazardous Locations Zone 1-2, Gas Group IIC-IIB-IIA T4 or Class I, Division 1-2, Group A, B, C, D T4 and connected via a single/redundant 2 wires data communication/supply line to a Modbus Gateway unit model D2050M, mounted in Safe Area/Non Hazardous Locations and connected to a PLC, DCS or PC. Multiplexer D2030M units can be installed in the field, close to input sensors, for data acquisition of signal from Hazardous Area/Hazardous Locations Zone 0-1-2 or Class I, Class II, Class III, Division 1-2. The units are primarily intended for Hazardous Area/Hazardous Locations acquisition of voltage free contact or EN60947-5-6 proximity detectors. D2030M scans all channels and stores all data in a memory buffer, where they can be rapidly accessed by the Modbus Gateway D2050M unit. Each D2030M unit accepts directly up to 32 input channels. Four D2030M units achieve 128 inputs with a single Modbus Gateway D2050M unit. Redundant communication is obtained by dual data/supply interface line. Safety parameters mantain compatibility with Gas Group IIC or Gas Group A and B, even in redundant mode. All parameters are software configurable by serial commands via D2050M Gateway unit. Functions and serial commands for RS-232 and RS-485 protocols are provided in the instruction manual.