Chapter 3
Installation
MAN_105G_1.16
Page 72
If you want to send a value from the 105G to the host device, use a Fieldbus
Write
Mapping.
The input data from the Radio Interface (i.e. input data that has either come in from the radio
or from local I/O) will be transferred to the IN Area via the fieldbus write mapping. The host
device can then read this input data from the IN Area.
If you want to send a value from the host device to the 105G, use a Fieldbus
Read
Mapping.
The host device can write output data to the OUT Area. The output data from the OUT Area
will then be transferred to the Radio Interface via the fieldbus read mapping. The radio driver
can then either send this output over the radio or to a local I/O.
Several different configurable
transfer modes
are also available for fieldbus mappings to
ensure the I/O is formatted according to the requirements of the particular fieldbus protocol
or host device. The six possible types of Fieldbus Mapping are outlined in the table below.
4.8.2
Transfer Mode
Radio Interface registers are all 16-bit general-purpose input or output registers. That is,
analog inputs or outputs are stored as a 16-bit value. Digital inputs or outputs occupy a whole
16-bit register and are stored as either 0000(hex) or FFFF(hex) for compatibility with the
ELPRO Radio Protocol. However, the Fieldbus Interface may contain (depending on the
protocol) significantly less registers than the Radio Interface (see diagram above). Also,
certain protocols may require a different I/O structure than that used by the Radio Interface
registers. Consequently, depending on the fieldbus mapping transfer mode (see above table),
Radio Interface registers may or may not be compressed.
105G Module
IN Area
OUT Area
Radio Interface
Write
from
I/O
Reg
Read to
I/O Reg
Fieldbus Interface
Write from
Host
Read from
Host
Fieldbus
Profibus 244 Bytes
Modbus/TCP 2048 Bytes
Ethernet/IP allows 6 input
connections; each
connection Max 512 bytes
Modbus Plus 2048 bytes
DeviceNet 512 bytes
Profibus 244 Bytes
Modbus/TCP 2048
Bytes
Ethernet/IP allows 6
output connections; each
connection Max 512 bytes
Modbus Plus 2048 bytes
DeviceNet 512 bytes
10,000 x 16-bit
I/O Registers