Design Guide
Revision 1.12
1998-08-12
HMS F
IELDBUS
S
YSTEMS
AB
Page 13 (35)
4.2.1 Input Area (000h - 1DFh)
•
write only (application
⇒
AB-DT)
The number of bytes for input data is specified with the register pair 3F8h, 3F9h. By default the contents of
these registers are 00 40h for 64 bytes of input. Input is specified as: Data which is read from the
environment, and written to the fieldbus.
Changes to the size of the input area is only valid during initialisation.
4.2.2 Output Area (1E0h - 3BFh)
•
read only (AB-DT
⇒
application)
The number of bytes for output data is specified with the register pair 3FAh, 3FBh. By default the contents
of these registers are 00 40h for 64 bytes of output. Output is specified as: Data which is written to the
environment, and read from the fieldbus.
Changes to the size of the output area is only valid during initialisation.
4.2.3 Fieldbus Specific Area (3C0h - 3DFh)
•
read / write (AB-DT
⇐⇒
application)
This area makes it possible to access data and functions specific for the supported fieldbus. The area should
only be used if the application needs access to this kind of data. The contents and functions in this area
differs between the different ANYBUS modules. Not all ANYBUS modules uses this area.
The area is divided into four sub areas according the following:
Address
Name
Description
3C0h - 3C7h
Mailbox In
(8 bytes)
Mailbox area for sending data and commands to the
A
NY
B
US
module.
3C8h - 3CFh
Mailbox Out
(8 bytes)
Mailbox area for receiving data and commands to the
A
NY
B
US
module
3D0h - 3D7h
Configuration
(8 bytes)
Area for fieldbus and module configurations like
module address, baud rate, etc.
3D8h - 3DBh
Status
(4 bytes)
Area containing fieldbus and module status.
read only (AB-DT
ð
application)
3DCh - 3DFh
Bi directional Status
(4 bytes)
Area containing fieldbus and module status.
read / write (AB-DT
ïð
application)
