
LTDVE8CH– INSTRUCTIONS MANUAL
17
See
chapter 13
for details on operation with both Modbus and web browser.
9.1. Serial RS485 interface
For the serial RS485 interface, the controller implements a subset of the Modbus/RTU slave protocol
and operates, by default, at 9600 bits per second with even parity. The factory set Modbus address is
32 and it is saved in the controller non-volatile memory.
The Modbus address is one of the controller parameters and can be changed using any of the available
interfaces. The factory set Modbus address can be restored using the INIT button (see
chapter 10
for
a description of the INIT button functionalities).
Please note valid Modbus addresses for slave devices are in the range 1 to 247; remaining addresses
are reserved by the standard for special purposes and must not be used. It is of great importance to
ensure, at the time of assigning the slave address, that there are not two devices with the same address.
In such a case, an abnormal behaviour of the whole serial bus can occur, the master being then in the
impossibility to communicate with all the slaves present on the bus.
The activity of the serial RS485 interface is shown by a dedicated yellow LED next to connector P6.
9.2. Ethernet interface
The Ethernet interface allows to configure the controller using the Modbus/TCP slave protocol, the
Modbus/UDP slave protocol or the HTTP protocol. For the last option, the controller provides an
internal web server accessible by most common web browsers.
To use the interface, connect the controller using a standard Ethernet cable. The default parameters
for the communication are listed in the
Table 13
: default parameters for Ethernet communication
.
Parameter
Default Value
Host name
LTDVE8CH-20
DHCP
Disabled
IP address
192.168.0.32
Subnet mask
255.255.255.0
Default gateway
192.168.0.1
Preferred DNS server
192.168.0.2
Alternate DNS server
192.168.0.2
Modbus address
32
Modbus/TCP port
502
Modbus/UDP port
502
Table 13: default parameters for Ethernet communication
The IP address, subnet mask and DHCP use flag are some of the controller parameters and can be
changed using any of the available interfaces. The factory configuration uses the static IP address
192.168.0.32. The factory settings can be restored using the INIT button (see
chapter 10
for a
description of the INIT button functionalities).
10. Visual indicators
There are twenty-eight LEDs on the top panel of the controller and two LEDs embedded in the
Ethernet RJ45 jack. Some of them are used to show that power supplies are available, others are
pulsed when inputs and output are activated, while others are used to indicate activity on the