A large 3D machining program reaches the Okuma MX-45VA but cannot be executed because the OSP 700L has only 80 meters of program memory. Follow the program data from the source device to the execution store: the limiting hop is not the floppy disk or the PC; it is the control's finite bubble memory when the program is loaded through PIP.
Where does the program path stop?
For a normal PIP transfer, a floppy disk or PC supplies the file, the control receives it through its removable-media interface or RS-232 port, and the complete program is written into bubble memory. Execution begins from that resident copy. Changing the source medium does not change where the program must reside.
| Hop | Function | Capacity constraint | Commissioning check |
|---|---|---|---|
| Floppy disk or PC | Stores the source file | Source-medium capacity | Confirm that the file can be opened and transmitted |
RS-232 or floppy interface |
Carries the transfer | Link reliability and settings | Transfer a small known-good program without communication errors |
PIP |
Imports the program | Requires a complete resident program | Confirm that the imported file appears in control memory |
| Bubble memory | Stores the executable program | 80 meters on the stated installation | Compare the free-memory indication with the incoming program |
DNC-B |
Provides the streaming alternative | Requires the option to be fitted | Confirm that the option and its operating mode are present |
A floppy-to-USB replacement can simplify file handling, but it cannot make an oversized PIP program executable. The control still attempts to store the complete file in bubble memory. Check: load a small program through the intended source and verify that the displayed free memory falls after the load.
Is the physical RS-232 path ready?
Layer one first. Use the existing RS-232 path to remove the floppy disk from routine transfers before diagnosing program capacity. A failed transfer and a successful transfer that exceeds resident memory are different faults.
| Item | OSP 700L side | PC side | Required relationship |
|---|---|---|---|
| Port | RS-232 |
Physical or correctly adapted serial port | Compatible electrical interface |
| Address | Serial channel, not an IP address | Selected serial port | Both endpoints must use the intended channel |
| Timing | Read the configured serial rate and framing | Set the same rate and framing | Exact match |
| Flow control | Read the active handshaking setting | Configure the corresponding method | No buffer overrun or stalled transfer |
| Direction |
PIP receive operation |
File transmit operation | Receiver ready before transmission |
The evidence does not provide the serial rate, framing, handshake, cable pinout, or control setting identifiers. Read those values from the installed control and transfer software rather than applying defaults from another machine. Check: send a small known-good file, compare its beginning and end at the control, and confirm that the transfer completes repeatedly without missing or altered blocks.
Will the program fit through PIP?
Once the link passes a small-file test, make the capacity decision. The PC can hold and send a file larger than the control's memory, but PIP cannot execute it in pieces. The entire program must fit in bubble memory before cycle execution.
- Record the control's free program-memory indication before transfer.
- Remove obsolete resident programs only through the control's normal file-management procedure and record the new free-memory value.
- Attempt to load the production file using the proven
PIPpath. - If the load completes, verify that the complete program is present, including its final blocks.
- If the control rejects or truncates the load at the memory boundary, classify the fault as insufficient resident memory rather than an
RS-232transport fault.
The 80-meter figure is the control's stated program-memory measure; it is not interchangeable with a USB device's megabyte rating without the control's own accounting method. The control's free-space indication and a complete load test are the deciding measurements. Check: open the loaded program at its final block and confirm that memory remains available for the control's required operations.
Should the machine use more memory or DNC-B?
| Choice | Execution path | What it solves | Remaining limit |
|---|---|---|---|
Continue with PIP
|
PC to RS-232 to bubble memory |
Eliminates routine floppy handling | Complete file must fit resident memory |
| Upgrade bubble memory | Source to larger resident store | Allows larger programs to load conventionally | The upgraded memory remains finite |
Fit DNC-B
|
External source to streaming execution path | Addresses programs that exceed resident memory | Requires the control option and a compatible sender |
| Replace floppy with USB media | USB media to replacement reader to PIP
|
Changes file transport convenience | Does not expand bubble memory or create DNC-B
|
Memory expansion is suitable only when the largest planned program, plus operating margin, fits in the upgraded capacity. Three-dimensional CAD/CAM output can grow beyond any selected finite upgrade, so select DNC-B when program size is variable or routinely exceeds resident storage. A third-party serial storage device must explicitly provide an execution method compatible with this control; external storage connected to RS-232 is otherwise just another PIP source.
Check: identify the option on the actual control and obtain the installed memory capacity from the machine display or service documentation before purchasing media hardware or transfer software.
How should the selected path be commissioned?
- Back up the resident programs and control data required by the site's maintenance procedure.
- Prove the
RS-232cable, endpoint selection, framing, and handshaking with a small program. - For resident execution, load through
PIP, confirm the complete file is present, and record remaining memory. - For streaming execution, confirm that
DNC-Bis fitted and select the control's documented DNC operating mode. Configure the sender to the serial settings read from the control. - Test with a non-production program while observing whether data continues to arrive during execution. A file that transfers completely before execution is still using the resident-memory path.
- Test feed hold, restart, normal completion, and communication-loss recovery according to the machine's documented operating procedure before releasing the path for unattended production.
Do not use a newer Okuma control's storage architecture as a setup reference for the OSP 700L. Options, file systems, and execution modes differ between control generations. Check: after power cycling the communication equipment, repeat the small-program transfer or streaming test without changing settings.
How is the complete 3D program verified?
Verification must distinguish file integrity, path stability, and machine execution. For a resident program, compare the control copy with the source by file size, block count, checksum, or another comparison function actually provided by the transfer system. For DNC-B, monitor the sender and control through the full run so that a serial pause is not mistaken for normal machining delay.
| Test | Passing result | Failure points to |
|---|---|---|
| Small-file transfer | Repeatable, complete file | Cable, framing, port, or handshake |
| Maximum resident-file load | Complete final block and usable free memory | Bubble-memory capacity |
| Streaming observation | Program data continues during execution | Incorrect mode if the entire file preloads |
| Full dry run | No communication interruption or missing blocks | Sender stability, link settings, or recovery handling |
| Controlled production run | Normal completion at the final program block | End-to-end path or program fault |
Check: run the complete intended 3D program under the site's approved prove-out conditions and verify normal completion at the source file's final block.
FAQ
Why does an OSP 700L reject a program sent by RS-232?
If a small file transfers correctly but the production file does not, the likely boundary is the control's bubble memory. PIP requires the complete program to reside there before execution.
Why does replacing the floppy with USB not add program memory?
USB changes the source medium, not the OSP 700L execution store. A file imported through PIP must still fit in the stated 80 meters of bubble memory.
Why does a larger external storage device not provide drip feed?
Storage capacity and execution mode are separate. A serial storage device provides drip feed only when it implements a control-compatible streaming method rather than sending the entire file through PIP.
Why choose DNC-B instead of a bubble-memory upgrade?
A memory upgrade raises the resident limit but remains finite. DNC-B is the stated option for programs that must execute without fitting completely in resident memory.
How do I verify that DNC-B is really streaming?
Observe the sender during a controlled full-program run and confirm that it continues delivering blocks while the machine executes. Run through the source file's final block and verify normal program completion.