VEGA VEGACOM 557 Modbus protocol - Manual (Page 4)

4 VEGACOM 557 Modbus
Product description
1 Product description
1.1 Application
The VEGACOM 557 is an efficient and easy-
to-use interface converter (Gateway) for your
measurement applications. It is used for
conversion of the VEGA-specific protocols of
DISBUS and LOGBUS into standard data
formats.
The existing version is used for connection of
level or pressure measuring systems to
modbus compatible systems such as
- processing systems (DCS)
- personal computers (PC)
- stored program control (PLC).
In addition, it is used for connecting a PC for
configuration or visualisation via the VEGA
adjustment software.
If connection is made to modbus compatible
systems, there is the possibility of calling up
measurement data and status information of
the measuring systems via the master of the
Modbus system. The coupling of the Modbus
is made via the connections on the rear of the
instrument. This data traffic requires that
special measures (described in this manual)
be taken in setting up the master of the Mod-
bus. The data received in the master can be
visualised there or further processed for
control purposes. In restricted volume, si-
gnal conditioning, instrument-specific param-
eters can be outputted, modified and
returned again.
Via the PC interface on the front of VEGA-
COM 557, the VEGA visualisation software
"Visual VEGA“ or the VEGA configuration
software "VEGA Visual Operating“ (VVO) can
be operated. For these applications, the
coupling between VEGACOM 557 and a PC
is made directly with the connection cable
between the RS 232 interface (PC) on the
front of VEGACOM 557 and a standard Port
(e.g. COM1) of your PC. There is also the
possibility to provide a connection via mo-
dems.
1.2 Configuration
The component VEGACOM 557 is designed
in 19" technology with 5 TE width
(1 TE = 5.08 mm) acc. to DIN 41 494. It can
be used:
- in carrier BGT 596
- in VEGALOG 571 carrier BGT LOG 571
- in housing type 505.
The electrical connection of supply voltage,
DISBUS and Modbus is made via a plug
connection acc. to DIN 41 612 on the rear of
the component. The connection to LOGBUS
is made via an additional 5-pole plug connec-
tor mounted to the DIN socket.
A 9-pole SUB-D plug marked “PC” is located
on the front panel of VEGACOM 557. It is
used for connection of a PC via RS 232C to
VEGACOM 557.
The component consists of two boards:
- the basic board
- the additional board.
On the basic board, you will find the power
supply unit, the PC interface, the DISBUS/
LOGBUS interface as well as the connections
for the Modbus.
The additional board is screwed to the basic
board and includes the hardware of the Mod-
bus interface as well as the protocol-specific
programs.
VEGACOM 557 connections
Supply
Basic board Additional board
PC
interface
DISBUS
LOGBUS
Modbus