Expanded Message Frame Configuration/Evaluation Of Internal Drive Variables - Siemens SINUMERIK 840DiE sl Manual

01/2007

18.2 Expanded message frame configuration/evaluation of internal drive variables

18.2 Expanded message frame configuration/evaluation of
internal drive variables
18.2.1 Description of the function
NC system
variables
Specific
system variables
General
system variable
© Siemens AG 2007 All Rights Reserved
SINUMERIK 840Di sl Manual (HBIsl) - - 01/2007 Edition
To ensure that the internal drive variables are available for evaluation in the
NCK, these are transferred from the drive as additional process data (PDA) dur-
ing cyclic PROFIBUS communication and saved by the operating system in
system variables.
The additional PDA is appended at the end of the standard message frame.
PDA for expanded message frame
PDA: Standard message frame
PDA1
. . . . .
Fig. 18-1 Standard message frame with additional process data (PDA)
According to the selected functionality, for each axis the additional PDA is avail-
able on the NCK side in individual specified system variables or the entire frame
as an array of neutral data words via a general system variable. In both cases,
the system variables are read--only.
Select the required setting in the NC machine data:
MD 36730: DRIVE_SIGNAL_TRACKING[n] (acquisition of additional drive
S
actual values)
To transfer drive variables to individual system variables you must set the fol-
lowing machine data:
MD 36730: DRIVE_SIGNAL_TRACKING[n] = 1
S
The additional PDA must be configured in the message frame in the exact se-
quence specified in table 18-1.
Table 18-1 Specific drive variables
PZD Drive variables
x+1 Load
x+2 Smoothed torque setpoint (Mset)
x+3 Active power (Pact)
x+4 Smoothed torque- -producing current Iq
(IqGl)
The entire message frame with standard process data and additional process
data is transferred in a general system variable as an array of 16--bit integer
data words via:
MD 36730: DRIVE_SIGNAL_TRACKING[n] = 2
S
System variable: $VA_DP_ACT_TEL[n, a]
S
where n = Index: 0.2,...15
a = machine axis identifier.
18 840Di- -specific Data and Functions
PDA: Additional
drive data
PDAx PDAx+1 . . . . .
System variables
$AA_LOAD
$AA_TORQUE
$AA_POWER
$AA_CURR
PDAy
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