CNC Setup Utility Manual
P/N 70000490C - Machine Constants
2-84
All rights reserved. Subject to change without notice.
10-December-04
Direct Numeric Control Setup Parameters
The Direct Numeric Control Setup Parameter Group ranges from
MC_4060 through MC_4065.
The Direct Numeric Control (DNC) feature allows the operator to run a
program not stored in the CNC’s memory. Programs that are larger than
the CNC’s memory, usually generated from CAD or CAM software, can
be run. The program is sent via RS-232 from a computer, another CNC
or any other device capable of RS-232 communications.
NOTE:
For optimal performance and fewest limitations, transfer the
program to the CNC via RS-232 and then run it in Auto Mode,
rather than DNC.
Selecting a DNC Execution Mode
The
MC_4060: DNC Execution Mode
parameter tells the CNC to run the
transmitted data in Drip Feed or Buffered Mode. [Default: Buffered]
In
Buffered Mode
, the CNC stores incoming data in a buffer (Received
Buffer) until the buffer is full. Then, the data is transferred to the
Execution Buffer and the CNC runs the transferred blocks. While the
CNC runs the Execution Buffer data, it stores more data in the Received
Buffer. When all the data in the Execution Buffer have been run, the CNC
transfers the contents of the Received Buffer into the Execution Buffer
and continues to run the program. The Received Buffer fills up with new
data. The process continues until the entire program has been
transmitted and run.
In
Drip Feed Mode
, the program is transmitted via RS-232, one block at
a time. Blocks are run as soon as they are received. There is no initial
delay, but transmission and run times are slower.
Setting the Buffer Size
The
4061: DNC Buffer Size (in buff. mode)
parameter enables the user
to specify the amount of memory to be reserved for DNC in Buffered
Mode. The choices are:
16K
32K
[Default]
64K
128K
Max
“Max”
indicates that the control will intelligently estimate the maximum
memory allocation. Depending on the size of the program and the
amount of available RAM available on the CNC, Max might allow the
entire program to be transmitted before a run begins. [Default:
32K
]
