A past Library did not take a protection measures when various data was read and written, from the viewpoint that CNC/PMC and the personal computer were closely connected.
However, in case of Ethernet version, CNC/PMC and the PC are connected via Ethernet, and operated at LAN, and moreover, via Internet.
In this case, the person whom the system designer did not forecast at first might connect from LAN or the outside of the workshop.
The protection measures has been introduced to Ethernet version so that this person should not incorrectly access, and not destroy the data of NC by design, or by accident.
Among various data of NC, the protected data is as follows.
| Ladder program, C language executor, Macro executor, Order-made macro, PMC C language, Maintenance Information, Embedded macro |
| R [Internal relay], T [Changeable timer], K [Keep relay], C [Counter], D [Data table] |
MTB and the end user can separately set whether these data items are protected or are not protected on CNC.
This is preserved as bit type data of the NC parameter (thereafter, it is called, "Protection pattern data"), and adds password/key word to the NC parameter for the limitation to the access to this data.
The protection pattern data set at NC is preserved as master data. And, it is possible to set, and to change only on NC.
When the application of Ethernet version is executed, the copy image of a couple of protection pattern data is taken in the work area of the Ethernet board for the application.
The function terminates abnormally by error code EW_PASSWD(=17) in the Ethernet library by referring to the copy image of this protection pattern data when an application calles the function that accesses the protected data.
It is necessary to update the copy image of the protection pattern data beforehand to access data normally. (Refer to cnc_chgprotbit function)
This change is effective by the end of the application and the influence of a set change does not affect other applications.
| * | Please refer to cnc_getlockstat, cnc_chgprotbit function for get and set in the protection pattern data. |