PROFINET controller limit and network role
The 6GK7443-1EX30-0XE1: The CP 443-1 functions as a PROFINET IO controller on the S7-400 backplane, handling up to 4 PN IO controllers per module — the remaining IO devices are managed by additional CPs or the CPU's onboard PN interface. It supports ring redundancy with integrated redundancy manager function, so a media break on the PROFINET ring does not drop the IO devices — the switchover is seamless to the controller logic.
Backplane supply and power budget
Powered from the S7-400 backplane at 5 V DC, the module draws a nominal 7.25 W — well within the rack power budget for a single-width compact module. The 5 V supply tolerance is 5 %, so the backplane power supply must hold regulation within that band; a sagging rail can cause the CP to drop IO communication without a fault code.
Engineering tool and configuration
Configuration requires STEP 7 V5.5 SP3 or higher, or STEP 7 Professional V12 (TIA Portal) or higher — the CP is not supported by older engineering versions. The module is configured via the hardware catalog in TIA Portal; the PROFINET interface name and IP address are set through the device configuration, and the IO controller assignment is made in the network view.
Environmental tolerance for mill-floor deployment
IP20 protection means it belongs in a sealed enclosure; dust and conductive debris from the mill floor will short the backplane if the cabinet door is left open.