The Host - Wi-Gtwy-9-Xxx Link - Weidmuller WI-GTWY-9 User Manual

WI-GTWY-9-xxx Wireless Gateway V1.18

2.4 The Host - WI-GTWY-9-xxx Link

For the host device, the WI-GTWY-9-xxx "looks" like a single device (or a "virtual PLC"),
containing the I/O for the complete
wireless I/O system.
2.4.1 Modbus / DF1
DATABASE
DATA-BUS
I/O
The user selects whether the WI-
"VIRTUAL PLC"
GTWY-9-MD1 should act as a
Modbus Master or Modbus Slave or
"HOST DEVICE"
DF1 device.
The data type and baud rate of the serial communications must be configured at the WI-GTWY-
9-xxx to match the host. Data types can be 7 or 8 bit, even/odd/no parity, with 1 or 2 stop bits.
Data rates can be 300 - 19200 baud.
The full WI-GTWY-9-xxx database (4300 registers) can be accessed by the Host Device.
2.4.2 Profibus
The Profibus port has auto-detect of baud rate from 9600 bits/sec to 12Mbit/sec - no
configuration is required.
The Profibus units have internal hardware comprising the Profibus Interface. The Profibus
Interface handles all Profibus DP Network communications. The internal Radio Interface is
separate to the Profibus Interface, and handles all radio communications. I/O in the Radio
Interface is linked to I/O in the Profibus Interface in a flexible way via WI Series Configuration
Software.
The Profibus Slave interface provides a total of 416 I/O bytes, with a maximum 244 input bytes
and maximum 244 output bytes. A Profibus byte can contain 8 discrete (binary) values, or two
bytes can be used for a 16-bit analogue or pulse register. So the Profibus interface is limited to
1952 discrete inputs or 122 analogue inputs or a combination. The same applies for outputs.
For example, a Profibus host wants to read 800 discrete inputs (100 bytes) and write 400 discrete
outputs (50 bytes). This will take up 150 bytes of the Profibus Interface, leaving 266 left. The
remaining bytes could be used for 133 analogue I/O - up to 72 analogue inputs (244 – 100
discrete input bytes) plus 61 analogue outputs - or vice-versa.
The Profibus Master interface provides a total of 2048 input bytes and 2048 output bytes. A
byte can contain 8 discrete (binary) values, or two bytes can be used for a 16-bit analogue or
pulse register. So the interface is limited to 4300 discrete inputs (the limit of the WI-GTWY-9-
xxx database) or 1024 analogue inputs (the limit of the HMS interface) or a combination. The
same applies for outputs.
2.4.3 Ethernet
The Ethernet port automatically handles Ethernet communications at 10 or 100 Mbit/sec. An IP
address is entered so that other Ethernet devices can recognize the WI-GTWY-9-xxx.
The Ethernet units have internal hardware comprising the Ethernet Interface. The Ethernet
Interface handles all Ethernet Network communications. The internal Radio Interface is separate
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