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AN-X-TI-MAS
November 2011
Exchanging Scheduled Data with a ControlLogix
The AN-X-TI-MAS module supports multiple scheduled connections
with a ControlLogix processor over Ethernet.
The AN-X-TI-MAS module behaves like a 17-slot ControlLogix rack
with an ENBT/A module in slot 16 and generic modules in slots 0 to 15.
A ControlLogix processor can open scheduled connections to each of
these 16 generic modules. Each scheduled connection consists of up to
248 words of output data from the ControlLogix processor to the AN-X
and up to 250 words of input data from the AN-X to the ControlLogix
processor.
Each connection has its own RPI, from 5 to 750 ms. The default RPI is 5
ms.
In general, you should try to keep the number of connections small.
There is significant overhead in opening and maintaining each
connection.
You map the inputs and outputs for the I/O modules on the network to
these scheduled connections. AN-X can create the mappings
automatically or you can create the mappings manually.
Even better, you can have AN-X create the mapping file automatically,
then edit the file to better suit your application. For example, in order to
make the most efficient use of the available Ethernet bandwidth, you can
organize the data so that items that must update quickly are mapped to
connections with short RPIs and items that are less time critical are
mapped to connections with longer RPIs.
In addition, the AN-X module has diagnostic data that can be mapped to
ControlLogix scheduled input data.
The mapping file can also contain options that apply to the entire
configuration.
The mapping file can also contain comments. Anything after a
semicolon on a line is treated as a comment.
Mapping I/O Data
You map input and output data to the ControlLogix scheduled data by
creating a comma separated variable file that defines the mappings and
downloading the file to the AN-X.
The file consists of sections for each scheduled connection. Within each
scheduled connection there are definitions for the input and output data
for that connection that refer to the I/O module (base and slot) where the
data is to be found.
