8 thermocouple inputs, 40-pin front connector
The Siemens 6ES7331-7PF10-0AB0 is an SM 331 analog input module for the S7-300 family, providing 8 differential thermocouple inputs. It accepts types B, E, J, K, L, N, R, S, T, U, and C, with internal cold-junction compensation and parameterizable integration time. The module draws 100 mA from the 5 V backplane bus and up to 240 mA from the 24 V load supply, with a typical power loss of 3 W. It requires a 40-pin front connector for field wiring.
Conversion time and channel isolation
Basic conversion time depends on the number of active channels: up to 4 channels complete in 10 ms per module; with 5 or more channels the cycle extends to 190 ms per module. The module provides channel-to-channel isolation in groups of 2, plus isolation between channels and the backplane bus, tested at 500 V DC. Shielded thermocouple cable runs up to 100 m are supported. Diagnostic alarms, limit value alarms, and hardware interrupts are parameterizable per group or per channel.