Fig. 138: Connection of configurable digital inputs/outputs to the module CI521-MODTCP
The meaning of the LEDs is described in Displays
Chapter 1.7.4.1.8.2 “State LEDs”
Connection of resistance thermometers in 2-wire configuration to the analog inputs
When resistance thermometers (Pt100, Pt1000, Ni1000) are used, a constant current must flow
through them to build the necessary voltage drop for the evaluation. For this, the module CI521-
MODTCP provides a constant current source which is multiplexed over the max. 4 analog input
channels.
The following figure shows the connection of resistance thermometers in 2-wire configuration to
the analog input AI0. Proceed with the analog inputs AI1 to AI3 in the same way.
Device specifications
Communication interface modules (S500) > Modbus
2022/01/31
3ADR010278, 3, en_US
737