Siemens SINUMERIK 840D sl Function Manual page 172

Several Operator Panels on Several NCUs, Distributed Systems (B3)
Link communication
2.8.2 Reading drive data via link variables
Task
A system contains 2 NCUs called NCU1 and NCU2. The two NCUs are connected via an
NCU link. Several machine axes are connected to NCU1. Of these, axis AX2 is traversed in
an interpolatory manner as a link axis of NCU2. The actual current value of axis AX2 is to be
transferred via link communication from NCU1 to NCU2 for evaluation purposes. The figure
below shows the basic design of the system.
Requirements
The actual current value of axis AX2 can be read via system variable $VA_CURR. In the
case of PROFIdrive-based drives, the following machine data needs to be set for this
purpose:
MD36730 $MA_DRIVE_SIGNAL_TRACKING = 1 (acquisition of additional drive actual
values)
Setting the machine data makes the following drive actual values available:
● $AA_LOAD, $VA_LOAD (drive capacity utilization in %)
● $AA_POWER, $VA_POWER (drive active power in W)
● $AA_TORQUE, $VA_TORQUE (drive torque setpoint in Nm)
● $AA_CURR, $VA_CURR (actual current value of axis or spindle in A)
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Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions