21
20
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 in-
puts to digital values;
• control relays and generates the analog outputs as de-
termined by the setup configuration, displays alarm
condition;
In the
HI 24
series 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 23
series displays EC only.
The status of the meter is shown by the LEDs.
STATUS
LEDs
Control
Alarm
Green LED
Contacts LED (yellow) Red LED
OFF
----
ON
OFF
ON
ON
OFF
ON
ON or OFF
OFF
ON
ON
OFF
ON or OFF
Blinking
The meter exits control mode by pressing SETUP or CAL and
confirming the password. Note
that this command generates
a temporary exit. To deactivate
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, if available);
4) PID, high setpoint (high conductivity dosage, if available).
If M2= 1 then S2-H2 LA;
If M2= 2 then S2+H2 HA;
If M2= 3 then S2+D2 HA;
If M2= 4 then S2-D2 LA;
If M1= 1 and M2 = 2
then S1-H1 S2+H2, S2 LA, HA S1;
If M1 = 2 and M2 = 1
then S2-H2 S1+H1, S1 LA, HA S2;
If M1 = 3 and M2 = 2
then S1 S2+H2, S2 LA, HA S1+D1;
If M1 = 2 and M2 = 3
then S1+H1 S2, S1 LA, HA S2+D2;
If M1 = 4 and M2 = 1
then S1 S2–H2, S1–D1 LA, HA S2;
If M1 = 1 and M2 = 4
then S1–H1 S2, S2–D2 LA, HA S1;
If M1 = 3 and M2 = 4
then S1 S2, S2–D2 LA, HA S1+D1;
If M1 = 4 and M2 = 3
then S2 S1, S1–D1 LA, HA S2+D2;
where the minimum deviation (D1 or D2) is 0.5% of the maxi-
mum range value.
Note
Some setup codes are available depending on the model.
Note
When a wrong setup value is confirmed
or a wrong setup code is selected, the con-
troller does not skip to the next setup item
but remains in the current item displaying
a flashing “ERROR” indicator until the pa-
rameter value is changed by the user.
Note
In some circumstances, the user cannot succeed in setting a
parameter to a desired value if the related parameters are not
changed beforehand; e.g. to set a EC high setpoint to 10.0
mS the high alarm must be set to a value greater than 10.0
mS first.
