Target Point Monitoring; Analog Spindle - Siemens SINUMERIK 808D Function Manual

If the encoder limit frequency is exceeded, the IS "Referenced/synchronized" DB390x.DBX0000.4) is reset for the
measurement system and IS "Encoder limit frequency 1 exceeded" (DB390x.DBX0000.2) is enabled.
If the maximum encoder limit frequency has been exceeded and the speed subsequently falls below the encoder frequency
in MD36302 ENC_FREQ_LIMIT_LOW (% value of MD36300 ENC_FREQ_LIMIT), the spindle is automatically synchronized
with the next zero mark or the next BERO signal.
17.6.7

Target point monitoring

Function
During positioning (the spindle is in "positioning mode"), the system monitors the distance from the spindle (with reference to
the actual position) to the programmed spindle set position (target point).
Two limit values can be defined as incremental path (starting at the spindle set position) in the following machine data.
● MD36000 STOP_LIMIT_COARSE (exact stop limit coarse)
● MD36010 STOP_LIMIT_FINE (exact stop limit fine)
Regardless of the two limit values, the positioning of the spindle is always as accurate as the connected spindle
measurement encoder, the backlash, the transmission ratio, etc.
Exact stop zones of a spindle for positioning:
IS: Position reached with exact stop ...
When the limits MD 36000 and MD 36010 are reached, IS "Position reached with exact stop coarse" (DB390x.DBX0000.6)
and IS "Position reached with exact stop fine" (DB390x.DBX0000.7) are output to the PLC.
Block change with SPOS
If the spindle is being positioned with SPOS, the block change will be dependent on the end point monitoring with the IS
"Position reached with exact stop fine". All other functions programmed in the block must have achieved their end criterion
(e.g. axes ready, all auxiliary functions acknowledged by the PLC).
17.7

Analog spindle

Function
In the control system, an analog spindle is designed for machine running. The spindle is controlled through the rated analog
voltage ranging from +10 V to -10 V and two signals in terminals X21-8 and X21-9. The voltage has the corresponding
output on the control system.
The analog spindle supports an increment encoder (TTL encoder), which can be directly connected to the control system.
You can parameterize the encoder only of an analog spindle. When you set the parameter of the encoder with a step motor
shaft, alarm 26006 is thrown out.
Through MD30130 CTRLOUT_TYPE and MD30240 ENC_TYPE, you can switch the rated value output between an analog
spindle and an actual spindle. For an analog spindle without any encoder, MD30240 ENC_TYPE[n] must be set to zero.
Function Manual
01/2017
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