15-B Maintenance Mnl, GFZ-62075E/03 - Automation Service Srl

3. TROUBLESHOOTING AND ACTION TO BE TAKEN
B–62075E/03
3.3 Displaying Conditions Using the Self–diagnosis Function
To quickly determine a breakdown cause the following should be done.
First, it has to be determined whether the breakdown occurred in the NC internal section, or the PMC, or on
the machine tool side.
There are times when it appears that a breakdown has occurred even when a breakdown has not actually occurred.
For example, when the machinery ceases to operate because the control unit is waiting for an external
machine tool signal.
In this case, the condition of the interface between the CNC and PMC, or between the CNC and the machinery,
and the conditions within the CNC needs to be investigated.
The explaination on displaying the breakdown condition of the CNC using the self–diagnostics function is
shown below.
The following is an example of the five soft keys on 9” CRT/MDI unit. For a unit having 10 soft keys, such as
a 14” CRT/MDI unit, the operation is basically the same. For general key operations, refer to the Operator’s
Manual.
The following shows the five soft keys on a 9” CRT/MDI unit.
POSITION PROGRAM OFFSET PRG–CHK CHAPTER +
The names of the soft keys in the frames are displayed on the bottom line of the screen.
The + sign in the rightmost frame indicates that there are other soft keys which do not fit on the screen.
3.3.1 Diagnosis function for the interface with machine tools
The PMC sits between the CNC and machine tool and controls the logical relations for signals between them.
Because the PMC actually exists as a separate internal function in the NC control unit, the CNC interface signals
cannot be considered physical interface signals with the machine tool, that is DI/DO electric signals.
By using the self–diagnostics function, the logic state of each interface signal in the NC control unit can be displayed.
Signals F, G, X and Y indicated in Fig. 3.3.1 can be displayed.
Fig. 3.3.1 Interface Signals that can be Displayed Using the Self–Diagnostics Function
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