Process input data words PI1 to PI3 serve to transfer the parameters listed in the table below via the
process data channel. 32-bit values, such as e.g. the actual position, are transmitted in two process
data words. You may decide yourself in which process data word you wish to transmit the more
significant part (high) and the less significant part (low) respectively.
NO FUNCTION
SPEED
APPARENT CURRENT
SPEED [%]
POSITION LO
*)
POSITION HI
*)
STATUS WORD 1
STATUS WORD 2
*)
Setting not possible for MOVITRAC
®
31..., size 0
No Function
If you assign
NO FUNCTION to a process input data word, the inverter will not update this process
input data word. In this case, the MOVITRAC
®
31.. will always return a value of 0000hex to the higher
level control system.
Speed Actual Value (SPEED)
The
Actual Value Description PIx = SPEED setting causes the inverter to return the current speed
actual value to the higher-level automation unit in the unit [1/min]. Scaling of the speed actual value
see Section 3.3.5.
The speed actual value can only be returned accurately if the inverter can determine the actual motor
speed by means of a speed feedback facility. In a slip compensated application the difference to the
real motor speed depends solely on the accuracy of the slip compensation set by the user.
Apparent Current Actual Value (APPARENT CURRENT)
The
Actual Value Description PIx = APPARENT CURRENT setting causes the inverter to return the
apparent current actual value to the higher-level automation system in the unit [% In] (in per cent of
the inverter rated current). Scaling see Section 3.3.5.
Relative Actual Value of Speed (SPEED [%])
With the parameter set to actual value description PEx = SPEED [%] the inverter feeds the current
relative actual value of speed with the unit [% f
max
] back to the higher-level automation system. The
scaling of the speed setpoint is described in section 3.3.5.
The relative actual value of speed can only be returned excactly if the inverter can determine the actual
motor speed via speed feedback and is operated speed controlled. In the case of slip compensated
applications the deviation from the actual motor speed is determined only by the accuracy of the slip
compensation set by the user.
3
Inverter Control
with Process Data
MOVITRAC
®
31.. Fieldbus Unit Profile
19
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