Control Mode - Hanna Instruments pH 500 Series Instruction Manual

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 pH (for
pH 500) or 25 mV (for mV 600).
Note
The password cannot be viewed when SETUP is pressed
without entering the original password first. The default
password is set at "0000". In the event that the user forgets
the password, this can be reset to "0000" by pressing and
holding CFM and then pressing LCD and CAL DATA at the
same time when the pH controller is in normal operating
mode (idle or control with measurement displaying).
Note
When a wrong setup value is con-
firmed, the pH controller does not
skip to the next setup item but remains
in the current item displaying a flash-
ing "WRONG" indicator until the pa-
rameter value is changed by the user (the same is also true
for the setup code selection). In some circumstances, user
cannot succeed in setting a parameter to a desired value if
the related parameters are not changed beforehand; e.g. to
set a pH high setpoint to 10.00 the high alarm must be set to
a value greater than pH 10.00 first.
Note
For code numbers 40, 41, 42, the output is related to pH or
mV units depending on the model (pH process meters or mV
process meters).
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CONTROL MODE

The control mode is the normal operational mode for these
meters. During control mode pH 500 and mV 600 fulfill the
following main tasks:
• convert information from pH/ORP and temperature inputs
to digital values;
• control relays and generate the analog outputs as deter-
mined by the setup configuration, display alarm condition;
• RS232 management.
In addition, pH 500 and mV 600 can log working data
through RS232 connection. This data includes:
• pH, mV and
• last calibration data;
• setup configuration (also from PC).
The status of the meter is shown by the LED's on the right
STATUS
Control
OFF
ON
ON
Meter exits control mode by pressing SETUP or CAL and con-
firming the password. Note that
this command generates a tem-
porary 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 (acid dosage);
2) ON/OFF, low setpoint (base dosage);
3) proportional, low setpoint (base dosage, if available);
4) proportional, high setpoint (acid dosage, if available).
o
C measured values;
LEDs
Alarm Alarm LED (green) Relay LED (yellow) Red LED
---- ON OFF ON
OFF ON ON or OFF OFF
ON OFF ON or OFF Blinking
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