Siemens SINUMERIK 840C Installation Instructions Manual page 575

7 Drive Machine Data (SIMODRIVE Drive MD)
7.3.2 Drive MD (data description)
1719
Current actual value (effective) (as from SW 6)
Default value
–
Current actual value display. The signal can be output via DAC.
2 qact 2 dact
MD 1719 = i + i
1720
Default value
0000
This machine data displays the CRC (cyclic redundancy check) errors which have been
detected. The counter information is output on every read request and is 5 bits in width
(bit 4...bit 0 or counter content 0...31).
Note:
It cannot always be assured that the CRC errors are assigned to the appropriate drives. With
an incorrect address, the "wrong" module indicates the error (if present).
1721
Default value
0000
Display of the monitoring machine data "Diagnosis speed actual value". If an impermissibly
large speed deviation occurs within the sampling period, then the value of the machine data is
incremented. Sporadic responses by a few increments can be ignored since these do not
influence the speed controller. A high disturbance level will cause the contents of MD 1721 to
be increased repeatedly by several increments.
Possible causes of disturbances:
• Encoder shield not earthed
• Encoder defective
• Earth connection of electronics ground in MSD module faulty
• Motor earth not connected in MSD module
• Value entered for motor moment of inertia too high
• Evaluation electronics
Note:
The function is activated with MD 1610, bit 0, and the threshold entered in MD 1611.
1722
Default value
0
Display machine data for utilization of drive capacity. The display shows the ratio "torque
setpoint M to present torque limit M
d
Smoothing to obtain a steadier display of the signal can be set in MD 1251, time constant
motor load.
7–160
Lower output limit Upper output limit
–
CRC diagnosis parameter
Lower output limit Upper output limit
0000
Diagnosis speed actual value
Lower output limit Upper output limit
0000
Capacity utilization
Lower output limit Upper output limit
-100000.0 100000.0
" Values lower than 100% indicate system reserves.
dmax.
©
Siemens AG 1992 All Rights Reserved
Units
– A
Units
FFFF Hex
Units
FFFF Hex
Units
%
6FC5197- AA50
SINUMERIK 840C (IA)
07.97
Active
at once
eff
Active
at once
Active
at once
Active
at once