VISORNET - Installation
I-14
Doc. DM245-I
Rev. 7.0
disappears, which will permit you to detect sabotages as well. This must not be set
above 30 V to avoid device damage.
Electric current supply
There is also optical insulation in this case. The range of electrical currents detected is
from 2 mA to 40 mA. The criterion to follow is the same as above.
4) Output device connection
The outputs consist of a contact (relay) that can be activated or deactivated. Each
output has a connector with three contacts (Sal 0,…, Sal 5. See Figure 1.7). One is
common, another is usually open and when activation is produced, this contact closes
the common contact. The third contact is usually closed, and when the activation is
carried out, it opens the contact with the common one. U.O. and common or U.C. and
common are connected respectively depending on the type of device.
The LD2, …, LD7 LEDS are switched on when the associated output is activated.
Control Block
The control block has programmable logic and a microchip. Its function consists of
reading the status of all the inputs and writing the status of all the outputs. When the
appropriate order is received from the remote center via the RS-485 interface, it reads
the status of the inputs and transmits it. When the order from the remote control to
write the outputs is received, it adds the value indicated to them. In all these
exchanged messages, the device needs to check they are addressed to it. To do this, a
character in the information header contains the identifying number of the device the
message is addressed to or the device which it came from. This identification is vital,
as one or several input/output devices can be connected to the same twisted pair.
The identification number is chosen in each device using a microswitch located on the
inside.
RS-485 Interface
The interface used is the RS-485. Here several devices can be connected to the same
transmission line. It is important to point out that only one of them can transmit at a
time. To achieve this, the control center (PC), will poll the different devices, giving
them instructions or examining them one by one. The communication will be carried
out at a fixed speed of 4800 bps, N-8-2.
The CLESA module has a group of 3 jumpers (JP1, JP2 and JP3) and a set of switches
(SW1), which are used to configure a series of boards over a single RS-485 bus.
The functions of these elements are:
JP1 bus termination Jumper
JP2, JP3 bus continuation Jumpers
SW1 configuration Switch for module identification in the
bus
Table 1.3.Configuration elements of an RS-485 bus with various CLESA
modules
