SEW-Eurodrive MOVIPRO Ethernet/IP - 9 Modbus protocol (Modbus;TCP); 9.1.1 Mapping and addressing

9
Modbus protocol (Modbus/TCP)
Description
Manual – MOVIPRO
®
with EtherNet/IP™ or Modbus/TCP Fieldbus Interface
101
9 Modbus protocol (Modbus/TCP)
9.1 Description
Modbus/TCP is an open protocol based on TCP/IP. It was one of the first protocol
types to become standard in industrial Ethernet interfaces for process data exchange.
Modbus/TCP has the following characteristics:
• Modbus frames are exchanged via the TCP/IP port 502.
• Every fieldbus master IP address is accepted.
• Modbus exclusively uses the "Big Endian" coding (Motorola data format or high
byte first).
• Access via "Peer Cop" is not possible. This is why it must be ensured that the
used fieldbus master supports the "IO Scanning" function.
9.1.1 Mapping and addressing
The logic Modbus address range is 64 k words and is addressed via the reference
number (offset). Four different tables can be in the address range:
• Digital inputs (RO)
• Digital outputs (RW)
• Input register (RO)
• Output register (RW)
The tables can be separated or overlapping.
The device provides the following data ranges:
• For process data transfer, there is a table that allows for write access (for setpoint
values) as well as read access (for actual values).
This table starts at offset 4 and ends at OFF
hex
. The cyclically transferred process
data words lie therein (1 – 8 for MOVIPRO
®
SDC and 1 – 120 for
MOVIPRO
®
ADC).
• An additional table is created by the PLC for the process output data words. The
table allows for one or several clients reading the current setpoints e.g. for visualiz-
ation.
This table starts at offset 104
hex
and ends at Offset 1FF
hex
.
• A third table is created to parameter access.
This table begins at offset 200
hex
, ends at offset 2FF
hex
and contains four words of
the MOVILINK
®
parameter channel.
• The remaining address scope from offset 400
hex
to FFFF
hex
is reserved and must
not be addressed.
The data word at offset 219
hex
(8606
dec
) is a special case, it allows for writing (and
reading) the timeout monitoring time.
INFORMATION
With controllers by Schneider Electric, observe that the address range often starts at
40001
hex
. This corresponds to the value "0" for the offset.
16998413/EN – 12/2016