Siemens 420 manual Setpoint channel, Summation and modification of the frequency setpoint AFM

3 Functions Issue 07/04

3.12Setpoint channel

The setpoint channel (refer to Fig. 3-39) forms the coupling element between the setpoint source and the motor control. MICROMASTER has a special characteristic which allows the setpoint to be entered simultaneously from two setpoint sources. The generation and subsequent modification (influencing the direction, suppression frequency, up/down ramp) of the complete setpoint is carried-out in the setpoint channel.

MOP
ADC
FF	Additonal
	setpoint
USS	SUM	AFM	Limit	RFG	Motor
BOP link					control
USS	Main
COM link	setpoint
CB
COM link
Setpoint source	Setpoint channel				Motor
					control

Fig. 3-39 Setpoint channel

3.12.1Summation and modification of the frequency setpoint (AFM)

Parameter range:	P1070 – r1114
Warnings	-
Fault	-
Function chart number:	FP5000, FP5200

For applications where the control quantities are generated from central control systems, fine tuning is often required locally on-site (correction quantity). For MICROMASTER, this can be very elegantly realized using the summation point where the main and supplementary (additional) setpoint are added in the setpoint channel. In this case, both quantities are simultaneously read-in via two separate or one setpoint source and summed in the setpoint channel. Depending on external circumstances, the supplementary setpoint can be dynamically disconnected or switched-in to the summation point (refer to Fig. 3-40). This functionality can be used to advantage, especially for discontinuous processes.

MICROMASTER 420	Operating Instructions
110	6SE6400-5AA00-0BP0