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Installation Manual LOGS50 EN_MI_090221
1.9
RS485 COMMUNICATIONS
LOGS50 equipment also counts on a local communication network RS485
compatible for enabling remote devices connectivity. This communication
network uses a MODBUS RTU mode protocol, where LOGS50 works as
master- so it is the logger the one that makes a request to a slave element
which after making the requested actions answers with a response frame.
The communication configuration used for RS485 NODBUS RTU is as follows:
9600 bauds, 8 bits, 1 stop bit and No parity
.
The implemented functionality in MODBUS RTU mode for local communication
is restricted to read outs of variables from the slave elements. To do so it is
used the public function MODBUS 04H (Read Input Registers).
In no case it is permitted to write in output registers.
The functionality of this communication goes to sleep mode being therefore
non-operative when it is not necessary the access to remote variables of the
slave elements.
The RS485 MODBUS RTU communication remains disabled when a Bluetooth
communication is ongoing- during that time no petitions via RS485 are
processed.
1.10
POTENTIAL FREE OR SOLENOID OUTPUTS
LOGS50 units include a total of two potential free outputs or dry contacts,
formed by contacts of their corresponding relays. These relays are bi-stable
latch type so once their state is fixed, they do not consume maintenance
energy.
In a task, when the activation of a certain output is specified, it implies the
contact closure from the associated relay. A contact opening is done through a
task which deactivates the output.
The technical details for those outputs can be found in the
Specifications
chapter.
Depending on the model the outputs can also be solenoid outputs presenting on
the terminals for some milliseconds [+ 12 VDC and, – 12 VDC] for opening and
closing electro valves.
The ±12 VDC volts are obtained by means of charging and discharging a 4700
µF capacitor.
