Programming manual
402
CNC 8070
14.
CNC VARIABLES
Understanding the description of the variables
(SOFT V02.0X)
356
EXEC – Access to the variable during preparation or
execution
The CNC reads several blocks ahead (preparation) of the one being
executed in order to calculate in advance the path to follow. This prior
reading is known as "block preparation".
Certain variables are accessed during block preparation whereas
others are evaluated when they are executed. The latter interrupt
block preparation.
(V.)G.PRGF Feedrate by program in G94. Evaluated during
preparation (before executed).
(V.)G.FREAL Actual (real) CNC feedrate. Evaluated when being
executed.
For variables accessed from PRG, the "Exec" column indicates
whether the variable is read or written during block preparation or
when being executed.
Yes When being executed. It interrupts block preparation.
No During preparation.
Accessing the variables from PLC or INT always interrupts block
preparation.
Interrupting block preparation may result in compensated paths
different from the ones programmed, undesired joints when working
with small sections, interruptions when working with look-ahead, jerky
axis movement, etc.
Use the #FLUSH instruction to force the evaluation of a variable when
it is being executed.
Sync / Asyn – Synchronous or asynchronous access from
the PLC.
PLC access to the variable, both for reading and writing, may be either
synchronous or asynchronous. A synchronous access is resolved
immediately whereas an asynchronous access takes several PLC
cycles to resolve.
The asynchronous variables are:
• The tool variables will be read asynchronously when the tool is
neither the active one nor in the magazine.
• The tool variables will be written asynchronously whether the tool
is the active one or not.
Example of how to access asynchronous variables
Reading of the radius value of offset ·1· of tool ·9· when it is not
in the tool magazine.
<condition> AND NOT M11 = CNCRD (TM.TORT.[9][1], R11, M11)
The M11 mark is set to "1" at the beginning of the operation and
it keeps its value until the end of the operation.
DFD M11 AND CPS R11 EQ 3 = ···
It waits for the consultation to end before evaluating the data.
To Next Page
Loading...
