User manual

Chapter 2 OPERATION
Page 23 ©February 2009
The full 105G 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 E-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 105G 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 105G.
The Ethernet units have internal hardware comprising the Ethernet Interface. The Ethernet
Interface handles all Ethernet Network communications. The internal Radio Interface is separate
to the Ethernet Interface, and handles all radio communications. I/O in the Radio Interface is
linked to I/O in the Ethernet Interface in a flexible way via E-Series Configuration Software.
The Ethernet Interface provides a total of 2048 input bytes and 2048 output bytes. An Ethernet
byte can contain 8 discrete (binary) values, or two bytes can be used for a 16-bit analog or pulse
register. So the Ethernet Interface is limited to 4300 discrete inputs (the limit of the 105G
database) or 1024 analog inputs (the limit of the Ethernet interface) or a combination. The same
applies for outputs.
For example, an Ethernet host wants to read 500 analog inputs (1000 bytes). The remaining
input bytes (1548) could be used for 12,384 discrete inputs - but the 105G database is not this
big. Provided there are no outputs required, there could be 3800 discrete inputs (4300 – 500
analogs). If there are outputs required, then the number of discrete inputs available will be
further limited.