Temperature controller for S7-300 racks
The Siemens 6ES7355-2CH00-0AE0 is an FM 355-2 C closed-loop controller module for the SIMATIC S7-300 platform, handling four analog inputs configurable for thermocouple types B, E, J, K, R, and S, as well as Pt 100 RTD sensors. It accepts voltage signals from -10 V to +10 V and current signals from 0 to 20 mA or 4 to 20 mA, making it suitable for direct connection to standard process transmitters without external signal conditioners. The module draws power from a 24 V DC backplane supply and dissipates up to 7.8 W, which should be factored into the rack's total power budget.
Mechanical fit and wiring constraints
Unshielded sensor cables can run up to 600 m, but thermocouple and 80 mV signal runs are limited to 50 m with shielded cable to maintain signal integrity. Digital inputs interpret 13 to 30 V as signal "1" and -3 to +5 V as signal "0", with a typical input current of 7 mA at signal "1".