Siemens SINUMERIK 840D sl Function Manual page 372

Detailed Description
2.3 Travel to fixed stop with analog drives
2.3 Travel to fixed stop with analog drives
2.3.1 SIMODRIVE 611 analog (FDD)
Current/torque control
The torque control and limit mentioned in the following text is realized with
611 analog (VSA) as current control and -limit.
Fixed clamping torque
A fixed current limitation is preset in the drive actuator by means of a resistor circuit (or via
R12). This current limitation is activated by the control via a PLC output (which acts on
terminal 96 of the actuator), thus ensuring that a fixed clamping torque is available on the
axis.
Setpoints can be injected via terminals 56/14 or 24/20.
Programmable clamping torque
In this case, the PLC switches the drive actuator from speedcontrolled into currentcontrolled
operation as soon as the fixed stop is reached.
Activation of terminal 22 causes the voltage level applied to terminals 20/24 to take effect as
a current setpoint rather than a speed setpoint.
The NC is thus able to specify a variable clamping torque.
Setpoints must be injected via terminals 24/20.
References:
/IAA/ Installation and start-up guide SIMODRIVE 611 analog System
36
Basic logic functions: Travel to fixed stop (F1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0