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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 analog output is frozen at its last value and control and
alarm relays are disabled. The “Hld” indication 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 automatically after a few
seconds to the “Hld” indication.
PRESETTABLE TIMER (CLEANING FUNCTION)
A timer is presettable by software to close a digital insulated
contact (terminals #5 on page 7) after a user programmable time
interval with a minimum interval of 1 day (e.g. for probe cleaning
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.
WATCHDOG
When a dead loop condition is detected a reset is automatically 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.
