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41
CONTROL MODE
The control mode is the normal operational mode for this
meter . During control mode
HI504
fulfills the following
main tasks:
• convert information from pH/ORP and temperature inputs
to digital values and show them on the display;
• control relays and generate the analog outputs as deter-
mined by the setup configuration;
• display alarm condition;
• perform cleaning actions according to the relays configu-
ration;
• start and stop hold mode according to the programmed
control timing;
• RS485 management .
In addition, the meter can log working data through RS485
connection . These data include:
• pH, mV and
o
C measured values;
• last calibration data;
• setup configuration (also from a remote workstation);
• event data .
In a normal situation, during control mode, the green LED
is ON and the error LED (red) is OFF . The red LED is never
fixed ON and blinks only upon an error .
The green LED is associated to the alarm relay and is OFF
if the alarm is active .
To deactivate the control mode set CONTROL ENABLE to
“OFF” in setup menu (CONTROL (“CtrL”) group) .
When measurements are in overflow, the upper or lower
range limit is shown on the LCD with blinking digits .
RELAY MODES
There are four relay options that can be configured through
the setup menu to perform different tasks .
Once enabled, relays 1 and 2 can be used in four modes:
1 . setpoint 1 (Analog output #1 must be set to recorder,
“rECO”);
2 . setpoint 2 (Analog output #2 must be set to recorder,
“rECO”);
3 . simple cleaning;
4 . hold mode .