VEGA VEGACOM 557 Modbus protocol - Manual (Page 21)

VEGACOM 557 Modbus 21
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
Multiple plug Basic board
Bottom view of VEGACOM 557
DIL switch
basic board
Front
plate
DIL switch blocks
additional board
Additional
board
2 1
1 2 3
Hook switches
additional
board
Adjustment possibilities for DIL switch block 1 on the
additional board
Switch adjustments on VEGACOM 557
3.2 Adjustment of the Modbus inter-
face
Three 8-pole DIL switch blocks as well as two
hook switches for configuration of the Mod-
bus interface to the DCS or the PLC are lo-
cated on the additional board.
The following adjustments for the Modbus are
made via these DIL-switch blocks:
Switch 1
- selection of the interface type
- activation of the bus termination
- selection of the protocol
Switch 2
- selection of the baud rate
- number of data bits
- mode for parity bit
- protocol mode (Modbus)
- definition of the measured value image
Switch 3
- Modbus address of VEGACOM 557
Note:
When holding VEGACOM 557 for adjustment
of the DIL-switches 1 to 3, the following
switch representation can directly imple-
mented.
Note:
When selecting the interfaces TTY and
RS 232, the hooks switches must also be set
to the respective position.
Activation of the bus termination on RS 485 is
necessary if VEGACOM 557 is the last par-
ticipant on the Modbus. General rule: The first
and the last bus participant must be oper-
ated with the bus termination activated.
When selecting interface RS 422, the bus
terminator must as a rule be activated on
VEGACOM 557.
DIL switch block 1
(additional board)
Selection of the interface type
Bus termination for RS 485/422
Protocol selection
TTY
RS 422, RS 485
RS 232
On
Off
Modbus
(RTU and ASCII)
Factory setting
1 2 3 4 5 6 7 8
ON