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ID-GmbH
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-Industrielle Datenerfassung |
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A DNC-Network for Windows
Today’s made-to-order manufacturing processes and the time pressure of just-in-time production necessitate system-overlapping and computer-integrating production control and monitoring. In conjunction with its’ users, a DNC-interface was created which is simple to use, flexible and easily adapted to company specific requirements. This interface is situated at the seam between design construction and production integrating the requirements of both areas. IDDNC is a new generation DNC-system which, in contrast to conventional DNC-system, is distinguished by its’ modular arrangement into functional components thus achieving maximum flexibility and functionality. WinDNC is the central administration software for IDDNC. It has a clearly arranged windows surface and is equipped with clear user interface and high operating comfort. WinDNC offers a multitude of very useful functions for the administration and processing of NC-programs, all aimed at saving precious time:
IDE-DNC is the DNC-transfer software for IDDNC. It can be run both on specially developed DNC-terminals suitable for industry and on standard PC-hardware. The use of sophisticated multitasking enables DNC-terminals to carry out up to eight simultaneous data transfers in the background as well as administrative tasks in the foreground. Configuration takes place by means of the central administration program WinDNC.
The central administration software for IDDNC under Windows The DNC-system IDDNC is controlled and managed through the Windows network-program WinDNC. WinDNC’s functions can be grouped into the following three general task areas:
A high level of operating comfort has been achieved thanks to the windows user interface enabling the user to easily learn how to operate the system through the utilisation of symbolic switches. Moreover, WinDNC is also equipped with a context sensitive help system that is at hand for help and advice at any time. Due to its’ capability of networking, WinDNC’s extensive functions are available directly at the CAD/CAM-Workstation. This enables the administration of NC-programs to be controlled from there and also an assessment can be made of the status of the DNC-system within the manufacturing process. If required, it is also possible to create a direct port to CAD/CAM-systems, which results in a fully automated reception and registration of NC-programs taking place in the background. The actual DNC-operation is carried out solely by DNC-terminals in production, irrespective of whether or not WinDNC has been called up on the network. Both components merely access a common data base. On the one hand, this guarantees a high level of protection against breakdown through the use of modular and exchangeable components. On the other hand, it enables all manipulations and administration tasks to be carried out completely parallel to the running DNC-operation.
Ä Administration of commissions Commissions are set up for the administration of NC-files. Each commission is allocated a commission index into which NC-files are entered. Any valid network path can be used as an index. Specific operating system characteristics (UNIX, VMS, DOS) are automatically taken into account. In order to describe the commission, a comment consisting of several lines is used along with the name of the contact person and deadline/appointment date. This information can be called up at any time by using an info key and it can be printed in the form of a commission index that contains all necessary information regarding content and NC-files in tabular form. In order to save NC-data onto backup systems, backup and restore functions for each commission are available.
To process commissions, a special dialog window is opened which contains all important functions for further processing of NC-programs. During the first step, data is taken into the commission. To do this, all available source disk drives (local disk drives and network disk drives) along with files appear in the field on the left of the dialog window whereas the field on the right displays the "NC-status list". This list displays the NC-files that have been stored in the commission including additional information regarding status. In order to integrate programs into the commission, the required file is selected from the source list and the copy switch is activated. Moreover, files from the commission can be backed up onto different parts of the disk or onto floppy disk or they can be deleted.
Ä The processing of NC-programs If, on looking more closely at the NC-programs of a commission, one would like to manipulate the former, this can be achieved by choosing the required file or files from the NC-status list and activating the required function. Depending on the choice of file, the appropriate switch panels symbolising the different functions appear in the dialog window named "Processing of commission". Copying/moving/deleting of files
Registering of files
Releasing and blocking of files
The displaying of files with the NCBrowser or the editing of files with the NCEditor
Moreover, for ease of viewing, program lines are highlighted in colour so that, for example, a technology sequence with an altered feeding rate can be distinguished straight away from a positioning sequence. The NCBrowser and NCEditor support the MDI-interface of windows so that several NC-files can be processed simultaneously and that, specifically in the editor, data can be exchanged via the clipboard.
The NCBrowser serves, among other things, to set entry points which enable the accurate entry into a NC-file e.g. after a cutter failure. In order to carry out this function, effective search functions are needed to find the required entry point as quickly and as easily as possible. A number of different strategies are available for this purpose:
Over and above this, the NCEditor offers a NC-typical "search and replace"-function which allows technology values such as feed rate and R.P.M. to be changed specifically. Data manipulations such as flipping an axis, translating of zero point, scaling and permutation of axes can be carried out. The NCEditor also disposes of an automatic store function which, after a specifiable interval, carries out the storing of all changes made so far. It also has an Undo-function which allows the changes made to be undone a line at a time. Ä Administration of DNC-terminals Configuration of DNC-terminals
Control monitor for DNC-terminals
Re-Entrance strategies in IDDNC M The Problem: Cutter failure Many modern mould design companies largely rely on 3D-CAD/CAM-systems to design their moulds directly in steel. To achieve this, CNC-machine controls often have to process large quantities of data (size range: Mbytes). Right in the middle of overlong cutter programs there is a cutter failure and the machining has to be resumed at the beginning. Unfortunately, there are only very few machine controls capable of offering an elegant and not very time consuming method of entry into such a NC-program. The use of a DNC-system with a fast and practicable possibility of entry will achieve considerable time savings. J The solution: IDDNC Thanks to years of close co-operation with our clients, we have developed a very elegant method of entry within IDDNC which was derived from the experience of the mould and toolmaking industry. In principle, the following steps have to be carried out for entry:
Steps 1. and 2. are supported by the WinDNC program with the aid of its’ NCBrowser, by numerous search functions and colour contrasting of NC-sequences. Once the required point has been located, an entry point is stipulated there. Altogether, up to five entry points can be defined and stored simultaneously. After all, by activating an entry point, IDE-DNC/CronDNC is informed to execute steps 3.-7. automatically during subsequent transfers of this file. The activating and deactivating of entry points can take place either through WinDNC or directly at the terminal through IDE-DNC/CronDNC. Entry for the NC-file in question is continued until none of the entry points remains active any more.
The change of format in IDDNC M The Problem: Different Machine Controls Machine parks are often composed of a number of different machine controls due to differing requirements. This leads to the common situation where the machine that was supposed to process the program is already engaged with another urgent order. In that case, the NC-program has to be regenerated for the machine control in question by means of a post processor. This transformation takes time and burdens the design department with unnecessary recurring activities. J The solution: IDDNC On the basis of a given starting format, WinDNC and IDE-DNC/CronDNC are capable of transforming the desired end format for the respective machine control. This can take place either by a NC-change of format in WinDNC which is called up by the user or directly during transfer by IDE-DNC/CronDNC with the aid of online-change of format. This makes it possible, for example, to digitise on a copying mill with FIDIA-machine controls in binary format and then, via a change of format, to machine the program on a Deckel Dialog 11 machine control. Furthermore, programs that were originally programmed in plain language for a Heidenhain H415 can be machined on a Philips 432 machine control. The ideal situation for the application of a change of format is given when all NC-data providing systems store programs in a standardised format such as APT or CL-DATA. In this case, there is only one starting format and the end formats are determined by the requesting machine control. Each individual transfer channel is allocated its’ own starting format and end format with the aid of protocol-parameters in WinDNC. In a generalised form, individual NC-formats are freely definable and offer a wide variety of features and possibilities. To this, an extensive format-editor is available in which all features can be adjusted. Among other things, NC-formats are also needed for entry in order to advise IDDNC which NC-descriptors are to be filtered for entry and which values are persisting or non-persisting respectively. There are, for example, a number of G and M-functions which must be all called up in succession whereas with others, for example the feed rate, only the last value is of interest.
Administration of the various formats is made possible with the aid of efficient functions for copying and duplicating.
In the case of generalised NC-formats which contain no information on tools, feed rate and R.P.M., it is also possible to complement the original format with the missing technology values in order to achieve a NC-program that is capable of machining. Two types of formats can be distinguished for this, machine control formats and generalised formats. It is hence possible during a change of format from a generalised format into a machine control format to feed in the technology values via dialog box and, in addition, to program a translation of zero point, the flipping of an axis, scaling as well as a permutation of axes. This allows machine personnel to very easily and safely adjust mill-technical parameters themselves directly in the DNC-system and it helps to avoid additional post-processor runs of the CAD/CAM systems.
Change of format is stretched to the limit, however, when asked to convert machine control specific cycle call-ups and tool definitions between machine control formats. It is, however, perfectly suited for 3D-points and 2D-geometry programs.
The visualisation in IDDNC M The problem: Display of NC-sequences The production of a complex machining part often requires a large number of separate NC-files for the different stages of machining. A 3D-display of the toolpaths with dimension specification and a simulation run can help to obtain a better general view and avoid unnecessary requests or extensive paper documentation. The graphic display of activating an entry point into a NC-file helps to obtain a clearer view, especially when line numbers are repeated due to size. A small section of an already existing NC-program is often all that is needed to carry out a repair or to re-machine an area. In that case, you either have to run the larger program one more time or generate a new NC-program for this area with the CAD/CAM-system. In either case this means an unnecessary waste of time. J The solution: IDDNC The above reasons led to the integration of a graphic tool into the WinDNC surface which makes it possible to obtain a 3-dimensional visualisation of any NC-file in the form of toolpaths. The 3-dimensional perspective display is thereby supported by dynamic rotation and translation of the system of coordinates and all 2D-projections are supported by dimensioning. There is a zoom and section function available for all elevations/viewing angles. To facilitate orientation within a NC-file, the corresponding NC-sequences can be displayed by a clicking on the toolpath with the mouse. Three options are available for the display of the corresponding NC-sequences:
The display of the two windows (NC-View and NC-Browser) are fully synchronised so that both windows always show the current position within the NC-file no matter where it was accessed. With the aid of the cursor key, the arrow is moved back and forth line by line within the NC-file which allows you to run through the entire NC-file.
This tool is also capable of graphically setting an entry point. This gives you the clearest view over the course of the toolpaths enabling you to re-enter at a specific point of the contour.
A further feature of NC-visualisation is the function to display several NC-files simultaneously in a common system of coordinates. This enables a control of the connections of individual NC-files as well as their relative position to one another. The loaded NC-files are displayed in a list and can be activated and de-activated individually.
For the re-processing of NC-files, sections can be entered graphically by using limitation curves (2D-polygone tracks) within the standard machining planes (X-Y,X-Z,Y-Z). Several curves can be entered to define the zone to be machined. The limitation curves can refer to either the cutter centre or, alternatively, the cutter edge. Depending on the machining zone (inner/outer), a radius adjustment is carried out. The curve data can be stored and administered separately in ASCII-readable files. For the execution of the intersection, it is possible to cut out the zone either inside or outside the intersection. Between individual contour parts, the program recognises automatically whether or not it has to withdraw to the previously calculated "step-off" distance. The step-off distance can be optimised by the user. Rapid movements that lead through the section area but are only used as a lead-in movement, can generally be eliminated only above a maximal value or above the demarcation plane.
Finally, it is also possible to restrict the section area in the direction vertical to the machining plane by using minimum and maximum; this is to avoid plunging into or encroaching on other contour parts that are situated above or below. The actual calculation of a new toolpath only takes a few seconds and it can be followed and verified directly on the screen. Demarcation data and contour can be deleted individually thus allowing a fast check on different options until the desired target is reached.
It is standard to issue the result of the re-processing in the same format as the starting file; it is, however, also possible to produce it in any NC-format by means of a NC-change of format. Similar to entry, the calculation of the new NC-program also takes into account modification of technology, change of tools as well as G and M-functions which have since been programmed onto the omitted contour parts. Subsequently, the re-processing program can be called up and processed like any other NC-program. The transport software for IDDNC Data transfer of the DNC-system can be carried out on standard PCs and also on industry suited DNC Terminals which have been specifically designed for the use in the workshop. With DNC-capable machine controls, NC-programs can be fed in/out or processed straight from the terminals. This allows each terminal to operate up to eight machines simultaneously. The DNC-system knows all current DNC-protocols to communicate with DNC-capable machine controls. It also of course supports simpler machine controls. The DNC-terminals display all necessary information concerning commissions and the status of data transfer (transfer time, estimated remaining running time, quantity of data transferred or remaining quantity of data may be selected for each DNC-channel). Based on sophisticated multitasking, IDE-DNC makes it possible to transfer data with up to eight machines simultaneously whilst maintaining a very high capacity of data transfer. DNC-protocols of all current types of machine controls are supported. The following implemented protocols are among the most important:
IDE-DNC can also be operated with non-DNC-capable machine controls. Different kinds of hardware-handshakes and software-handshakes are hereby offered as a safeguard. Machine control specific particularities are firmly implemented in IDE-DNC and are adjusted according to the type of machine control that is linked up. Configuration takes place centrally through WinDNC. Capacity of data transfer IDE-DNC offers the cost effective possibility of linking up to 8 machine controls to each terminal. In that case, data transfer has to be sufficiently fast on all eight channels in order to avoid, for example, machining to catch up with data transfer during automatic recharge mode. Extensive tests and measuring results with machine controls of types Dialog 11, H425 and FIDIA with transfer speeds between 19200 and 38400 revealed that the maximum capacity of IDE-DNC even with eight linked-up machines is still approx. 20 % above the top data transfer rate that these mills could achieve individually under optimal conditions. This excellent result is due to sophisticated multitasking and the highly optimised IO-kernel of the program both of which make it feasible to achieve a maximal, actual transfer rate that lies only 2-5 % (depending on type of processor 80486DX/2 66 - 80386SX33) below the theoretical maximal value for each channel. By way of contrast, the actual transfer rate for machine controls usually lies 25-40% below the theoretical maximum rate. The use of the DNC-Terminal is menu-driven. To start a data transfer the DNC channel has to be selected first followed by the desired transfer function and finally the target commission. The status of the data transfer is visualised on the DNC terminal as shown in the following figure
Herein, the function keys F1-F8 are used to access the different channels. The transfer functions for the channel can then be selected using the port-command. In addition, a small data administration was incorporated for the display, release and blocking of files as well as, on request and with password protection, to be able to delete, copy and move them. These functions can be executed parallel to data transfers on other channels. Besides 4-port cards, IDE-DNC also supports 8-port RS232 or RS422 IO-cards, which means that up to 8 machine controls can be operated simultaneously. Furthermore, a client-server-version of IDE-DNC exists for special applications which provides full remote control of several transfer-PCs using a control surface via network. This allows these PCs to stand in a central and protected location.
DNC-options offer the possibility to further supplement and specialise the transport-software IDE-DNC in order to meet your requirements for a DNC-system. DNC-process
DNC-remote control
DNC-online change of format
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Provided that the
NC-file was registered for a specific type of machine control, the "NC-status
list" contains an index card symbol. 
In this state, the
file can be called up directly by the machine control using the internal program-number
(name). The symbol will change to a stylised machine if the file is at least once
successfully transferred to the machine control. 
In the eventuality
of a fault or cancellation e.g. due to cutter failure, a "fire" will also appear
on the milling table to symbolise a crash. 
Moreover,
program-linking for certain automatic recharge functions are shown as a chain symbol. Set
entry points for NC-files can be identified by an arrow into the index-card symbol. A dot
can be found after the status symbol which, depending on accessibility, appears either
green for released NC-files or red for blocked NC-files. 
Alternatively, it
is also possible to display the program number or the registered type of machine control
in the NC-status list instead of symbols. The sorting sequence of the list can be altered
as well.
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