In recent years, IS1, geared towards hazardous areas, provided many new functions, including Fast Ethernet connection, PROFIBUS redundancy, DTM support, integration of optical rings and modules with integrated magnetic valves. Introducing IS1+, R. STAHL presents a key innovation for this explosion-protected remote I/O system. The new I/O modules are fully downward compatible to their predecessors. They enable efficient solutions even at a low signal density and reduce the number of module types by 50%. The IS1+ range includes an eight channel analog I/O module with HART, a 16-channel digital I/O module and an 8-channel temperature module for resistance thermometers and thermocouples. The signals can be individually parameterized for each channel. Moreover, the company also supplies digital output modules, with an increased output power, suitable for most intrinsically safe magnetic valves. Designed for installations in zone 2 for connecting intrinsically safe field devices from zones 0 or 1, the series also comprises cost-optimized zone 2 I/O modules with an identical functional range. In addition, a new low power technology has been developed especially for the new IS1+ I/O level, which makes the modules suitable for an extended temperature range from -40 to 75°C and considerably extends their lifespan to up to 15 years. Diagnostics options have been considerably extended as well: all zone 1 modules are now equipped with one or two LEDs per channel. Analog modules signal line faults via a red LED, while digital modules additionally display the switching status via a yellow LED. This makes it much easier to locate errors directly on site. All modules feature additional self-diagnostic functions according to NAMUR NE 107, enabling them to send a “maintenance required” alert in time before an actual failure comes to pass. On top of that, the need for maintenance is clearly signalled by means of a blue LED at the module. The status bit for process signals which characterizes the quality of values as “good” or “bad” just like in fieldbuses is another new feature. As established by IS1, the new IS1+ generation is versatile and cost-efficient. Thanks to a consistently intrinsically safe structure with an intrinsically safe fieldbus, changes and extensions to the installed system are easily possible without shut-downs in hazardous areas (hot work / hot swap).