Evd120, Programming, 2programming – EVCO EVD120 User Manual
Page 11
11
EVD120
Programming
2
Programming
2.1
Preliminary remarks
EVD120 supports the MODBUS communication protocol.
The kind of network EVD120 can work in is RS-485 (look at Fig. 4); for further information on the realization of the
network, consult the Installation manual of RICS for Windows
®
(the document is available in the CD of RICS).
According to the standard settings:
•
the instrument address has value 247
•
the baud rate has value 9,600 baud
•
the parity has value even.
These parameters are hereinafter called “network parameters”.
2.2
Programming an EVD120 having standard network parameters using the soft-
ware RICS (adding an EVD120 having standard network parameters to an
existing and working network of instruments managed by RICS)
Operate as follows:
•
make sure the network is made of instruments that support the MODBUS communication protocol; to learn the
communication protocol supported by the instruments, consult the List of compatible instruments and supported
communication protocol (the document is available in the internet site www.evco.it)
•
make sure the network is made of less than 32 instruments
•
make sure no instrument in the network has value 247 as instrument address; to learn the instrument address,
consult the instructions (the document is available in the internet site www.evco.it)
•
make sure the baud rate of the instruments in the network has value 9,600 baud; to learn the baud rate of the
instrument, consult the instructions (the document is available in the internet site www.evco.it)
•
make sure the parity of the instruments in the network has value even; to learn the parity of the instrument, consult
the instructions (the document is available in the internet site www.evco.it)
•
quit RICS
•
disconnect the power supply of the instruments in the network
•
connect terminal “ + ” of the hardware driver of the last instrument in the network to terminal “ 1 ” of EVD120
(1)
•
connect terminal “ -- ” of the hardware driver of the last instrument in the network to terminal “ 2 ” of EVD120
(1)
•
connect terminal “ S ” of the hardware driver of the last instrument in the network to terminal “ 3 ” of EVD120
(2)
•
to reduce the reflections on the signal transmitted through the cable, plug in the termination of the first and last
element of the network
Fig. 4 - Example of RS-485 network.
[ EVD120 ]
Programming
(1)
use a twisted pair
(2)
pair, as far as possible, the ca-
ble to the ones you have already con-
nected