Siemens sinumerik 840D sl Function Manual page 517

Detailed description
2.2 Clearance control
(840Di)
SINUMERIK 840Di with I/O modules and drives connected via PROFIBUS-DP produces a
deadtime T
T
dead
cycle time + 2 * "PROFIBUS-DP cycle" + To
• Conversion time, channel cycle time:
• To
2.2.2 Velocity feedforward control
Eliminating the delay time
The closed-loop control gain, Kv, set for the position controller corresponds to a delay time
Δt. The display time, Δt, is the time which elapses until the actual position of the axis to be
controlled reaches the set position at a prescribed velocity of v.
and a closed-loop control gain Kv in seconds:
for an assumed closed-loop control gain Kv = 4, the corresponding delay time Δt is:
12
of:
dead
= 2 * position controller cycle + 2 * speed controller cycle + conversion time + channel
ET 200 S with "2 AI U high-speed" analog electronics module produces the following
times:
– Conversion time: 0.1 ms
– Channel cycle time: 1 ms (both channels)
→ Average control deadtime of 0.5 ms
To is the setpoint transfer time of the drive parameterized in SIMATIC S7: HW-Config.
Special functions: Clearance Control (TE1)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0