POSYC 3303 industrial PC
Installation, use and maintenance manual - EN
Ver. 1.02
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7.2 Environmental requirements
The POSYC is designed to be placed in a container that gives it protection from water and dust that could dam-
age it.
The internal cooling of the POSYC takes place through the air sucked sideways by a high speed fan; in order
for the system to work properly it must remain within the room temperature limits given in the specifications. All
this implies that within the panel that will surround the POSYC, there must be suitable conditioning systems to
keep the temperature within the accepted limits.
7.3 Electrical wiring
The main connections for the POSYC operation are the power supply and the earth; make these connections
following the instructions on polarity, conductors and connectors stated in the chapter “Connections”. Before
switching on the computer, make sure that the mains voltage is within the parameters indicated in the
specifications.
The device connection to the peripheral units is simplified by the use of standard computer connectors; this
means that all standard peripheral for personal computers can be connected by means of the cable supplied
with them or by means of commercial cables easily found on the market.
For connections to non-standard devices, such as inverters or other that require particular combinations of sig-
nals and cable lengths, it is possible to make them following the instructions stated in the chapter “Connec-
tions”.
The following are some recommendations on how to make the cabling for serial communication.
7.3.1 RS485 serial port wiring
The typical use of RS485 ports is in multipoint configuration, or more devices connected to each other; this type
of connection exploits a single pair of conductors and from this it follows that the communication is of the half-
duplex type.
Through the RS485 serial ports, up to 32 devices (including the master) can be connected in a single section,
offering good noise immunity and a maximum transmission speed.
According to the specifications of the RS485 standard the maximum length of the section is 1200mt at a max-
imum transmission speed of 100kbps. Please note that the length of the section is inversely proportional to the
communication speed.
