Rev. 02-21 Page 37
USER MANUAL
Description of operation:
The unit configured as Master constantly communicates with the connected slaves through the RS-
485 connection, indicating the quantity of steam to be produced (0-100%) and managing the
priorities of the various units in relation to discharges for deconcentration or testing.
The operating mode of the Master/Slave unit is only set on the Master by means of the variable S9,
as well as the possible connection of the ambient humidity probe, the humidity probe in the duct,
the 0-10V reference signal, the ON-OFF enablement and the humidity setting.
The variable Pr, which represents the percentage of steam production at full capacity, is instead set
on each individual unit.
The absence of consent (clamps 24 and 25 open on Master HUM2 board) behaves as follows:
-
On the Master unit, it stops the same Master unit and all the connected slave units (flashing
OFF).
-
On the Slave units, stop only the slave unit concerned (OFF flashing).
Stand-by by means of the dedicated key behaves as follows:
-
If activated on the Master unit, it puts the machine in stand-by mode (LED flashes on the
stand-by key) and brings the steam production request of the connected slaves to zero.
-
On the Slave units, it stops only the concerned slave unit by putting the machine in stand-by
mode (LED flashes on the stand-by key).
If the Master cannot communicate with a slave, after a 15-second timeout time it signals the
problem with an alarm that can be silenced (E7). The interrogation of the slave continues and if the
communication resumes, the error is reset automatically.
If a Slave is not queried by the Master within a timeout period of 15 seconds, it considers
interrupted the connection and therefore leads to 0 the production of steam, disconnecting the
electrodes and signalling the anomaly with an alarm that can be silenced (E7). If the connection is
resumed, the alarm is reset automatically and normal operation is resumed.
On the humidifiers configured as Slaves (MS = 1), the variable S9 is not considered; for them the
production of steam follows in a proportional way the data sent by the Master on the RS485
connection.
Management of priorities of discharges for deconcentration and tests:
The priorities for deconcentration discharges and for diagnostic tests are managed as follows:
The Slave units, when interrogated, send the eventual water discharge request to the Master that
manages them with a FIFO (first input / first output).
The Master waits 3 minutes before giving the next consent to the waiting unit, following the priority
in the FIFO; this allows the unit that is discharging the water to resume steam production.
The Slave unit that requested a discharge waits for the consent from the Master for 45 minutes, after
which it is executed anyway (Time out).
