Siemens SINUMERIK 840C Installation Instructions Manual page 487

7 Drive Machine Data (SIMODRIVE Drive MD)
7.2.2 FDD MD (data description - SW 3)
1707
Default value
0.0
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.
1708
Default value
0.0
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 µs)
and 40 ms (with a current controller cycle of 125 µs). 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).
1710
Default value
0.0
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.
1711
Default value
0.0
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.
7–72
Speed actual value
Lower output limit Upper output limit
0000
Smoothed current actual value
Lower output limit Upper output limit
0000
Significance current representation
Lower output limit Upper output limit
0
Significance speed representation
Lower output limit Upper output limit
0
©
Siemens AG 1992 All Rights Reserved
32 767.0 rev/min
32 767.0
32 767.0
32 767.0 rev/min
6FC5197- AA50
SINUMERIK 840C (IA)
09.95
Active
at once
Units
Active
at once
Units
%
Active
at once
Units
µA
Active
at once
Units