40
WATCHDOG
When a dead loop condition is detected a reset is automati-
cally invoked.
The effectiveness of watchdog capability can be tested through
one of the special setup items. This test consists of executing
a dummy dead loop that causes watchdog reset signal to be
generated.
EXTERNAL FUNCTIONS
HOLD FUNCTION
This function allows to perform the maintenance
procedures. When the relevant digital insulated
input (terminals #6 on page 7) is on, the ana-
log output is frozen at its last value and control
and alarm relays are disabled. The “Hld” indi-
cation is displayed on the secondary LCD when
the function is active. A 5 to 24 VDC voltage
can be applied to this input.
While in hold state, it is possible to display the
temperature reading on the secondary LCD
pressing the right arrow key. Only when the key
is released, the secondary LCD returns auto-
matically after a few seconds to the “Hld”
indication.
PRESETTABLE TIMER (CLEANING FUNCTION)
A timer is presettable by software to open a digi-
tal insulated contact (terminals #5 on page 7)
after a user programmable time interval with a
minimum interval of 1 day (e.g. for probe clean-
ing function). The time interval is programmable
in number of days through setup code 72.
This output is ON for the period set through setup code 77
(this period can be also changed when the output is ON).
The starting time of the cleaning timer can be set through
setup codes 73, 74, 75 and 76.
