Rockwell Automation 1794-APB/B FLEX I/O PROFIBUS Adapter Module User Manual - Manual (Page 100)

4–8 Configure the Adapter for Master/Slave Communication
Publication 1794ĆUM057B-EN-P - November 2001
On a PROFIBUS DP network, the I/O data exchanged between the
PROFIBUS DP master and a DP slave is encapsulated into logical
modules. The total I/O data exchanged between a PROFIBUS DP
master and a DP slave device comprises a set of logical modules
which is defined in the check configuration data.
Each physical slot of the FLEX I/O system is represented by two
logical modules (one input and one output). When the FLEX I/O
adapter is powered-up, the check configuration message configures
the module format (input and output words) and defines the size of
the modules within the device. When the sizes are configured, the
I/O data can be optimized to remove unused data from the data
stream.
Both input and output sizes can be configured. If a slot is empty, or if
either the input or output module is zero length, the specific
identifier for an empty module (free place) must be used.
If the end of the identifiers is reached before all slots have been
configured, the remaining slots are configured as empty.
The first two modules allocated are for the adapter itself, and must
always be a 1 word input module and a 1 word output module,
regardless of what parameter format you choose. The adapter uses
these words for adapter status information. Modules for each of the
individual slots (FLEX I/O modules) must also follow these word
assignments.
The format of the adapter status word is defined in the following
table:
Adapter Status Word
Input Status Word
Bit Position Name Description
0 Address Change This bit is set when the Node Address switch is
changed since power up.
1-7 Reserved Sent as zeroes.
8-15 I/O Module
Fault 1
This bit is set when an error is detected in a slot
position (bits 0-7 refer to slots 1-8)
Output Status Word
Bit Position Name Description
0-15 Reserved Sent as zeroes.
1 I/O Module Faults are caused by:
• transmission errors on the FLEX I/O backplane
• bad module
• removed module
• incorrect module inserted
The adapter expects the identifier area for each of the eight FLEX
I/O slots to be 2 bytes. The DP input/output identifier and all specific
DP identifiers (except the empty module) are not supported.
Entering Check
Configuration Data