User Guide

18
CONTROL MODE
The control mode is the normal operational mode for these
meters. During control mode the meter fulfills the following
main tasks:
• converts information from EC/TDS and temperature inputs
to digital values;
• controls relays and generates the analog outputs as deter-
mined by the setup configuration, displays alarm condition;
In HI 710 models it is possible to switch between EC and
TDS reading pressing “LCD”. The TDS value is obtained mul-
tiplying the EC measurement by the TDS factor set through
setup. The HI 700 models display EC only.
The status of the meter is shown by the LED’s on the right.
STATUS LEDs
Control Alarm Alarm LED (green) Relay LED (yellow) Red LED
OFF ---- ON OFF ON
ON OFF ON ON or OFF OFF
ON ON OFF ON or OFF Blinking
Meter exits control mode by pressing
SETUP or CAL and confirming the
password. Note that this command
generates a temporary exit. To deacti-
vate the control mode definitively, set
CONTROL ENABLE to “0” (item #
02).
RELAY MODES
Once enabled, the relays 1 and 2 can be used in four differ-
ent modes):
1) ON/OFF, high setpoint (low conductivity dosage);
2) ON/OFF, low setpoint (high conductivity dosage);
3) PID, low setpoint (low conductivity dosage);
4) PID, high setpoint (high conductivity dosage).