2 AO, HART, Ex(i) — what the specs mean for the loop
The Siemens 6ES7332-5TB00-0AB0 is a 2-channel analog output module for the S7-300 rack, delivering 0/4-20 mA per channel with HART communication active — indicated by a green LED per channel. Each output drives up to 650 Ω on current loops, with a no-load voltage of 19 V and short-circuit current limited to 66 mA — enough headroom for a 250 Ω HART resistor plus line drop in a 24 V loop. The module is rated for Ex(i) applications, with 1500 V AC channel-to-channel isolation and 60 V DC / 30 V AC between outputs and the internal M reference — genuine galvanic separation for hazardous-area barriers.
Panel integration — 40 mm width, 3.5 W dissipation
The module occupies a single 40 mm wide slot in the S7-300 DIN-rail assembly — standard width for a 2-channel analog output card. Typical power loss is 3.5 W, drawing 100 mA from the 5 V DC backplane bus and the field-side 24 V DC supply. The 60 °C maximum ambient temperature is the ceiling for the enclosure — no derating below that. Conversion time is 40 ms per channel, with a cycle time of 5 ms for all channels — suitable for process loops (valve positioners, I/P transducers) where sub-10 ms update is not required.