Eurotech PCN-1001, User Manual

Page: 79 / 118

Test
an RS485 connection and use the RS485_GUI PCN-1001 User manual
79
PCN-1001_UserMan_En_4.0
Test an RS485 connection and use the RS485_GUI
Introduction
Thanks to its RS485 ports, the PCN-1001 allows you to take advantage of all the benefits of an RS485 network,
including the possibility of connecting multiple devices – up to 32 at the same time – and perform
communications over long distances even in electrically noisy environments.
RS485 communications are based on a master/slave configuration:
• The master (a Host PC such as a laptop or, in a real situation, the main on-board computer that acts as
the Control Unit, for example a Eurotech DuraCOR system) begins communications by sending a
message to the slave devices
• The slave devices (the PCN-1001 devices) analyse the message, execute a command (if required) and
transmit the answer to the master.
The “
RS485_GUI ” is a program that, once installed on the Host PC, can be used to simulate a real RS485
connection.
Warning:
The parameters of the serial port on the Host PC and PCN-1001 must be equal (see ‘ Configuring the RS485
port of the PCN-1001’ on page 82)
Warning:
The PCN-1001 system does not include any line termination resistor, nor any fail safe bias resistors.
The two ends of the RS485 bus should include a termination resistor connected across the Data + and Data
– wires. Furthermore, one end of the RS485 bus should include pull-up or pull-down resistors to ensure a
fail-safe bias for each data line/wire when the lines are not being driven by any device.