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In the first two cases the configuration of Setpoint (1 or 2)
determines the operating mode of the relay . Once enabled,
the control relay can be configured to control as a ON/
OFF or PID control of the acid/base dosage .
A High-hight Alarm is imposed for acid/base dosage time
when the relays are energized continuously . This parameter
can be set through setup procedure (CONTROL group, set-
up item C .32) . When the upper time boundary is reached,
an alarm is generated and device stays in alarm condition
until relay is de-energized .
If the “hold mode” is selected for the relay, then it is en-
ergized only when the meter is in hold mode . In this case
there is no time boundary for the ON state of the relay .
The option for relays 3 and 4 can be configured to opera-
tions in three modes:
1 . simple cleaning;
2 . advanced cleaning;
3 . hold mode .
ON/OFF CONTROL MODE
Once a relay is enabled (set 1, set 2), the setpoint can be
configured to be activated as a high limit (“OOHI”) or as
a low limit (“OOLO”) . In both cases the following values
have to be defined through setup:
• setpoint value (pH/mV; setup item C .11 or C .21);
• hysteresis for setpoint (pH/mV value; setup item C .12 or
C .22) .
A control device can be wired to the contact output .
Connect the device to the COM and
NO (Normally Open) or NC (Normally
Closed) terminals of the relay .
The ON relay state occurs when relay is energized (NO and
COM connected, NC and COM disconnected) .
The OFF relay state occurs when relay is de-energized (NO
and COM disconnected, NC and COM connected) .
The following graph shows relay state along with pH mea-
sured value (similar graph can be derived for mV control) .
