The IM 174 is an isochronous PROFIBUS module of S7-300 design for operating up to four drives over PROFIBUS DP on a motion control PLC. These can be electric or hydraulic drives with analog setpoint interface (+/- 10V) or stepper drives with pulse direction interface. The Technology CPUs, the Microbox 420-T and SIMOTION C/P/D can be used as the motion control PLC. 
The actual values (encoder values) are transmitted from the IM 174 to the motion control PLC over PROFIBUS DP. The following encoders can be used:
- 5 V or 24 V incremental encoders or
- SSI absolute value encoders.
The position controller in the PLC calculates the speed setpoint. This value is transmitted over PROFIBUS DP to the IM 174, and output there.