PROFINET IRT timing and the 2-port switch
The Siemens 6ES7155-6AU00-0BN0 is the IM 155-6PN Standard interface module for the ET 200SP distributed I/O system. It runs PROFINET IRT with send cycles from 250 µs to 4 ms in 125 µs increments — deterministic enough to hold the micron in a coordinated servo group, no jitter in the loop for the motion controller. The two RJ45 ports include an integrated two-port switch with autonegotiation and autocrossing, so the line topology daisy-chains without external switches. The module supports media redundancy via PROFINET MRP and LLDP for topology discovery.
I/O module count and power budget
This interface drives up to 64 I/O modules in an ET 200SP station — 48 via the backplane bus and an additional 16 ET 200AL modules via BU/BA send. That covers most distributed machine builds without a second interface. The module draws 1.9 W typical from the 24 V DC supply. Inrush current hits 3.7 A max, and the I²t let-through is 0.09 A²·s — relevant for sizing the upstream SELV supply and the protective circuit breaker's magnetic trip threshold. Firmware is V3.3. The module supports I&M data I&M0 to I&M3, PROFIenergy, prioritized startup, shared-device operation, and security level 1 per Test Cases V1.1.1. Diagnostics and alarms are standard.
DIN-rail footprint and status indicators
PROFINET connectivity uses a pluggable BusAdapter — the BA 2x RJ45 or BA 2x FC. The module supports 100 Mbit/s full duplex (100BASE-TX) only; 10 Mbps is not supported.
Quoted to order against the BOM quantity.