What this BaseUnit does on an ET 200SP rail
The 6ES7193-6BP40-0BA1 is a SIMATIC ET 200SP BaseUnit — Type A1, single-slot — that physically mounts an I/O module and routes its signals to the backplane bus and field wiring. It carries 16 process terminals for the I/O module plus 2x5 add-on terminals (CC74 compatible) for auxiliary connections like shields or external power. The push-in terminals accept 0.14 mm² to 2.5 mm² (AWG 26–14) solid or ferruled wire, so no screwdriver needed for termination — just strip to 8 mm and press in. It also integrates a temperature sensor for module-level thermal monitoring.
Fit and mounting constraints
At 15 mm wide and 141 mm tall, this BaseUnit snaps onto the standard 35 mm DIN rail and occupies one slot position. Depth is 35 mm — that's the space from the rail to the front of the terminal block, so account for it in your enclosure depth planning. It bridges the potential group from the left and does not create a new potential group, meaning it continues the same 24 V DC supply rail from the adjacent left-side BaseUnit. The and bus bars carry up to 10 A; the process terminals are rated at 2 A max. For the 24 V DC supply lines, Siemens calls for an external miniature circuit breaker rated 24 V DC / 10 A with type B or C tripping characteristic.
Environmental limits and derating
Horizontal installation permits ambient temperatures from -30 °C to 60 °C; vertical installation derates the max to 50 °C. Installation altitude goes up to 5 000 m, but above 2 000 m you need to follow the manual's restrictions for reduced air density and cooling. The isolation is type-tested at 707 V DC — that's the dielectric strength between the bus and field circuits, not an operating voltage.