905U-G Wireless Gateway
User Manual
Page 95
©September 2004
Extended Words 1 ... 8
These registers are specific for each command. Consult the specification for each command
for further information.
Message Interface Addressing
Command messages and response messages are allocated fixed locations in the radio
interface (I/O Registers). Also, spontaneously generated alarm messages are allocated unique
fixed locations in the radio interface. The memory allocation of these messages in the radio
interface is outlined in the table below.
I/O Register
Purpose
4550 - 4689
Message IN Area (i.e. Messages to send
to
Profibus Interface)
4700 - 4839
Message OUT Area (i.e. Messages
from
Profibus Interface)
4850 - 4899
Spontaneous Message OUT Area (i.e. Alarm Messages
from
Profibus)
4900 – 4949
Spontaneous Alarm ACK IN Area (i.e. ACK
to
above)
For example, a message could be sent to the Profibus Interface by constructing the required
message in the “Message IN Area”, either via radio using appropriate block mapping(s) or
locally via a host device or configuration tool. This message is activated upon change-of-state
of the Message ID field (see “Message Structure” above). The profibus interface may
generate a response to this message in the “Message OUT Area”, which may then also be
transmitted via radio using appropriate block mappings or locally via the host device.
