User manual

105G Wireless Gateway User Manual
Elpro_man_105g_1.18.doc Page 78
network. For I/O transfer between the radio network and the fieldbus network, I/O Registers in
the Radio Interface must be linked with registers in the Fieldbus Interface using configuration
software.
Depending on the fieldbus protocol, the size of the Fieldbus Interface may be limited (for
example, the Profibus Slave interface supports only 416 bytes I/O). The Radio Interface
supports 10,000 registers, of which 4300 are general-purpose I/O registers. Each Radio Interface
register is 16-bit, even for discrete (or “digital”) input or output values. The Fieldbus Interface
comprises a block of 8-bit bytes (referred to as “locations”). Digital I/O can be packed - each
fieldbus location can hold 8 digital inputs or outputs. Analog or pulse values can be stored as a
low resolution 8-bit value (a single fieldbus location) or as a high resolution 16-bit value (two
consecutive fieldbus locations).
To optimize I/O usage, the 105G provides a flexible method of data transfer between the Radio
Interface and the Fieldbus Interface. The user configures links between the Radio Interface and
Fieldbus Interface via Fieldbus Mappings in the E-Series Configuration Software. The diagram
shows in more detail the relationship between the Radio Interface and Fieldbus Interface.
Gateway Module
IN Area
OUT Area
Radio Interface
Write
from
I/O
Re
g
Read to
I/O Reg
Fieldbus Interface
Write from
Host
Read from
Host
Fieldbus
RESISTOR
Profibus 244 Bytes
Modbus/TCP 2048 Bytes
Ethernet/IP allows 6 input
connections; each
connection Max 512 bytes
Modbus Plus 2048 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