Rail fit and port count
The 6GK7377-1AA00-0AA0 is a SIMATIC S7-300 device-design unmanaged switch that snaps onto the S7-300 rail. Four electrical ports, each running 10 or 100 Mbit/s, with no managed switching or multiport mirroring.
Supply and power budget
Runs on 19.2 to 28.8 VDC through a 2-pole terminal block, drawing 0.07 A max — negligible load on the rack power supply. Dissipates 1.6 W, so no forced-air concern in a sealed IP20 enclosure.
Environmental and approvals
Operates 0 to 60 °C, stores and transports at -40 to +70 °C. IP20 protection — panel-only, no washdown. Carries ATEX II 3 G Ex nA (KEMA 06 ATEX 0021 X) and UL 1604 / UL 2279-15 for hazardous locations, plus marine approvals DNV, NK, and LRS. EMC immunity per EN 61000-6-2:2001, emission per EN 61000-6-4:2001.