Hanna Instruments HI 504 - Manual (Page 39)

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The information about SIM charge and expiration date are
not saved in the SIM card but are managed by the network
operator; the instrument can not get directly the information.
To prevent the discharge of the SIM card, the user has to
configure manually (accordingly with the credit stored on the
SIM card) the maximum number of SMSs that can be sent
(item P.04).
Note Every time an SMS is submitted, the item P.04 is updated and
it will always indicate the remaining number of messages that
can be sent by the instrument.
When the number of remaining messages is going to reach
zero (the lower limit depends on the value of item P.05), the
message “Rem_msg: xxx; Maximum number of Sms reached.
Please check the HI 504 SIM card charge level” will be sent
by the instrument to the programmed phone number(s). This
particular situation is managed as an error occurrence and
a confirmation of the SMS reception is waited.
In this case the user is supposed to extract the SIM card from
the cellular module as soon as possible and to check the
remaining credit (using its own cellular phone and calling
the network operator).
When a confirmation is given to the message, the “Cellular
error” is switched on and no more messages will be sent by
the instrument in case of error occurrences. To disactivate the
“Cellular error”, it is necessary to modify the item P.04.
Every time a recharge of the cellular module SIM card is
performed, the corresponding expiration date has to be manu-
ally updated in the Setup menu (items P.07 - P.09). A check is
performed daily between the current (see “Real time clock”
subgroup in Setup menu) and the expiration date. Two weeks
before the expiration date, the message “Rem_msg: xxx; The
HI 504 SIM card will expire on: DD-MM-YYYY. Please re-
charge or substitute it” is sent to the programmed phone
number(s). The same message will be sent again also one
week before, and the day before the expiration date.
Note This particular warning message does not need confirma-
tion.
In this case the user has to recharge or substitute the SIM
card. The sending of the repeated warning messages will be
and no confirmation waited), while the P.06 item sets the
delay (in minutes) between two subsequent messages.
When the instrument receives a phone call (coming from
one of the programmed cellular numbers), it interprets the
calling as an information request and answers hanging up
and sending an SMS with its current status report (number of
remaining messages, pH or ORP and temperature values,
current active errors). The message will be as for example:
“Rem_msg: 150; pH: 8.32; Temp: 25.8; Alr set1; Rel on”.
The maximum number of characters for an SMS is 160, so
that, if many errors are active, it is possible that the message
be truncated. To avoid this problem, a coded notation is
used to identify the active errors.
Here is the list of the error strings coded notation:
• Alarm for setpoint 1: “Alr set1”
• Alarm for setpoint 2: “Alr set2”
• Max relay ON time error: “Rel on”
• Life check error: “Life chk”
• pH electrode broken or leakage: “pH brk”
• Reference electrode broken or leakage: “Ref brk”
• Old pH probe error: “Old prb”
• Dead pH probe error: Dead prb”
• Calibration time-out error: “Cal tout”
• Temperature probe broken error: “Temp brk”
• Digital transmitter error: “Tx err”
• Cellular error: “Cell err”
• Power reset error: “Pwr rst”
• EEPROM corruption error: “EEPr cor”
• Watchdog error: “Wtc dog”
• Temperature level error: “Temp lvl”
If no error is active, then the correspondent string will be:
“No error”.
If at the information request the instrument is in Hold mode,
the “Hold” string is added before the pH (or ORP) indica-
tion. If the instrument is performing a cleaning action, The
“Cleaning” string is added before the readings information.