Siemens SINUMERIK 840C - Manual (Page 487)

7 Drive Machine Data (SIMODRIVE Drive MD) 09.95
7.2.2 FDD MD (data description - SW 3)
Speed actual value 1707
Default value Lower output limit Upper output limit Units
0.0 0000 32 767.0 rev/min
Active
at once
This machine data is used to display the actual speed value and represents the unfiltered
actual speed value. Time-synchronous unlatching (scanning) of machine data MD 1706,
MD 1707 and MD 1708 is not provided. The appropriate machine data is unlatched by the
MMC request "Read variables" via the STF ES communications interface.
Smoothed current actual value 1708
Default value Lower output limit Upper output limit Units
0.0 0000 32 767.0 %
Active
at once
This machine data is used to display the smoothed current actual value. The torque-producing
current actual value is smoothed by a PT1 element with constant coefficients. These
coefficients correspond to time constants of 20 ms (with a current controller cycle of 62.5
µ s)
and 40 ms (with a current controller cycle of 125 µ s). In this case, the smoothed current actual
value is displayed as a percentage. 100 % corresponds to the maximum current of the power
section (e.g. with an 18/36A power section 100 % = 36A RMS).
Significance current representation 1710
Default value Lower output limit Upper output limit Units
0.0 0 32 767.0 µ A
Active
at once
This machine data is used to display the significance of the current representation. The
significance of bit 0 (internal current actual value representation) is shown to the user to allow
allocation of the internal current status representation to the physical ampere values. The
maximum power section current is present internally in normalized representation.
Note:
This machine data is calculated only once during ramp-up; its value cannot therefore be
changed during operation.
Significance speed representation 1711
Default value Lower output limit Upper output limit Units
0.0 0 32 767.0 rev/min
Active
at once
This machine data is used to display the significance of the speed representation. The
significance of bit 0 (internal speed actual value representation) is shown to the user to allow
allocation of the internal speed status significance to the physical revolution values. A speed is
present internally in the units of the encoder system and referred to the current speed
controller clock cycle.
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SINUMERIK 840C (IA)