Siemens SINUMERIK 828D Function Manual page 1257

Preconditions
A spindle position actual-value sensor is absolutely essential for M3/M4/M5 in connection with:
• Revolutional feedrate (G95)
• Constant cutting rate (G96, G961, G97, G971)
• Thread cutting (G33, G34, G35)
• Tapping without compensating chuck (G331, G332)
• Activate position control (SPCON, M70)
A spindle position actual-value encoder is not required for M3/M4/M5 in connection with:
• Inverse-time feedrate coding (G93)
• Feedrate in mm/min or inch/min (G94)
• Tapping with compensating chuck (G63)
Speed control mode
Speed control mode is particularly suitable if a constant spindle speed is required, but the position of the spindle
is not important (e.g. constant milling speed for even appearance of the workpiece surface).
• Speed control mode is activated in the part program with M3, M4, M5 or with SPCOF.
• The following NC/PLC interface signal is set:
DB31, ... DBX84.7 (control mode)
• NC/PLC IS:
DB31, ... DBX61.5 (Position controller active)
is reset if position control is not used.
• Acceleration in speed control mode is defined independently of the gear stage in the machine data:
MD35200 $MA_GEAR_STEP_SPEEDCTRL_ACCEL
The value should reflect the physical circumstances, if possible.
Position control mode
Position control is particularly suitable if the position of the spindle needs to be tracked over a longer period or if
synchronous spindle setpoint value linkage is to be activated.
• Position control mode is switched on in the part program with: SPCON(<spindle number>)
• The following NC/PLC interface signal is set:
DB31, ... DBX61.5 (position controller active)
• Acceleration in position control mode is defined independent of the gear stage in the machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
S1: Spindles
16.2 Operating modes
1257