Siemens SINUMERIK 840D sl Function Manual page 1389

Variable addressing
For some NC variables, it is necessary to select area no. and/or line or column in the NC
VAR selector. A basic type can be selected for these variables,
i.e., area/column/line are preset to "0".
The contents of the area number, line and column specified by the NC VAR selector are
checked for a "0" in the FB. If a "0" is present, the value is transferred to the input parameter.
The user must supply the required parameters (UnitX/ColumnX/LineX) before calling
FB PUT.
Machine data, GUD
In order to define machine data and GUDs without a password, the protection levels of the
data you want to access must be redefined to the lowest level.
The process is described in the /IADC/ Commissioning Manual, "Protection level concept" or
/PGA/ Job Planning Programming Manual, "Define protection levels for user data (GUD)".
Notice
FB 3 can only write NC variables if basic program parameter "NCKomm" has been set to "1"
(in OB 100: FB 1, DB 7). The call is permitted only in cyclic program OB1. An assignment for
all parameters with Req = 0 is also permitted in OB100.
When channelspecific variables are written, only variables from one and the same channel
may be addressed via Addr1 to Addr8 in a job (FB 3 call)
.
In areas V and H, different logic axis numbers must not be assigned in a single job. (Failure
to observe this rule results in Error : = TRUE, State:=W#16#02).
NCK variables within one group can be combined in a job:
Group 1
Group 2
Group 3
The same rules apply to channels 3 to 10 as illustrated as examples in the above table in
groups 1 and 2.
Note
Especially when reading several long strings, the number of usable variables can be less
than 8.
Basic logic functions: PLC basic program solution line (P3 sl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Area
C[1] N
C[2] N
V[.] H[.]
Detailed description
2.12 Block descriptions
B
Q
B
Q
T
T
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