FANOX SIA-B Series, Руководство пользователя

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7.
COMMUNICATION AND HMI
7.1. Front Communication: USB
One communication port is installed on the front of the relay. The connector that is used is a micro
USB. The protocol that is used is Modbus RTU (19200 -8bit
– no parity – 1 stop bit). The protocol
map and documentation that are used are attached in an appendix to this manual.
To write commands it is necessary to set up a communication session (identification command)
which it will be closed after a period of time without communication. To set up a communication
session it will be necessary a password. To write commands the password will be adjusSetting
group.
7.2. Rear communication: RS485
An option exists to fit the SIA-B with a rear communications port RS485, which must be specified
when the model is selected.
The RS485 port output has two terminals (+, -), located on the rear of the relay. The protocol that is
used is Modbus RTU or DNP3.0 Serial (19200 -8bit
– no parity – 1 stop bit).
This port can be used to continuously monitor the relay from a remote PC or SCADA system. Up to
32 pieces of relay can be connected to one bus; each piece with a different Modbus address. The
relay Modbus address can be configured using the SICom program.
To minimize communication errors because of noise, the use of a stranded and shielded cable is
recommended for the physical connection. All the + terminals on one side, and all the - terminals on
the other must be connected together in order to make the connection.
Resistors should be used at each end if very long cables are used. The best solution for avoiding
reflection is to install resistors at both ends of the cable. The ohm value of these resistors must be
equal to the cable impedance value.
Fiber optics can be used in very aggressive environments, and they are connected by using the
corresponding converters.
Connection diagram for a RS485 bus:
Minimum required current to achieve remote communication:360 mA (single phase), 180 mA (2-
phase) and 120 mA (3-phase).