The Siemens 6ES7157-0AG82-0XA0 is a PROFIBUS PA segment coupler in an IP66 field enclosure, linking up to 8 PA field devices to a main line at 31.25 kbit/s. It sits between the DP/PA coupler and the field instruments, providing diagnostics, spur line status, and automatic bus termination.
Temperature range and power budget
Rated for ambient operation from -40 °C to 85 °C, so it can live in freezers or hot enclosures without derating. Power consumption maxes at 4.1 W (typ. 544 mW), and the coupler draws up to 514 mA from the loop or auxiliary supply. Each PA spur line is limited to 60 mA; the coupler supports eight devices, so total spur current must stay under 480 mA. Reverse polarity protection is built in, but only when paired with the FDC 157 power conditioner.
Field mounting and wiring
Enclosure dimensions: 360 x 120 x 83 mm (width x height without screw glands x depth). IP66 keeps it clean for wash-down or outdoor locations. Automatic bus termination on the main line means no jumper or resistor to install — the coupler handles it internally. PROFIBUS PA main cable must be Type A; spur lines also Type A. The coupler includes a status indicator and diagnostics function, plus main line failure reporting.