ConMed ExcaliburPLUS PC - Page 73

Watchdog Timer (dIA1) mode solves that prob-
lem by using the microprocessor as an on-board
programmable pulse generator to allow selection
of one of three pulse frequencies. One of the
selections places pulses continuously inside the
normal Watchdog Timer window, while the oth-
ers are too early and too late. It is also possible
to set RLYENA to verify operation of the lockup
circuitry.
4.7.3.1 Accessing Watchdog Timer
Diagnostics
Since this mode is useful only with the RLYENA
flag in the reset state, “dIA” will not appear in the
menu once RF has been activated in any of the
power calibration modes. On the other hand, if a
faulty WDT is detected on initial entry to CAL
MODE, Watchdog Timer (dIA1) will be auto-
matically entered, bypassing the menu, since
proper calibration may be impossible if the WDT
is faulty.
To enter Watchdog Timer (dIA1) voluntarily,
enter CAL MODE per Section 4.6.1 above, then
select “AIA” in the Cut window and “1” in the
Coag window. Then press the “STORE” button.
Entry will be signified by “1” appearing in the
Bipolar Power window.
The menu cannot be restored from this mode.
When work is complete, exit CAL Mode by using
the RST switch or by powering down. This
mode has no effect on the NOVRAM, so the cali-
bration and CRC are unchanged.
4.7.3.2 dIA 1 Mode Selection
An indication of the currently selected mode
appears in the Bipolar Power window. Modes are
selected by using the Bipolar Power Adjust keys.
Table 4.7 lists the available modes and the
response for a normal unit.
4.7.3.3 Troubleshooting with Watchdog Timer
(dIA1)
Since the WDT timing accuracy and ability to
interrupt RF output are verified by the micro-
or on every power up, there is no need to
k these parameters periodically. The only
feature not checked automatically is lockout,
which is extremely reliable due to its simplicity:
If the unit declares an Err 4.X in RUN mode,
then the timing is incorrect. For large timing
errors, the Err Code may not correctly indicate
the problem stage. In that case Watchdog Timer
(dIA1) should be used. Select Late Mode 2 to
observe timing of both WDT one-shot stages at
their test points. Stage 1 should go high for 9 to
[DISPLAY /WDT PERIOD WDTSTB2 /WDTINT
|& MODE (msec) First Stage Second Stage
(A3TP8) (A3TP2)
1 12.0 High for period of High
Normal first one-shot.
Nominally 10 msec.
2 20.0 Same as Mode 1 High for period of
Late second one-shot.
Nominally 15 msec
3 2.0 High Low
Early
4 12.0 Same as Mode 1 High until Mode 2
Lockup* until Mode 2 or 3 or 3 is selected,
is selected. Then Then latched to Low.
*RELYEN-Q (A3TP5) is Low until Mode 4 is entered. At that time, it is latched High.
Table 4.7 dIA 1 Modes
re 4-19