ProSoft Technology inRAx MVI56-CAS User Manual page 25

Installing and Configuring the Module
This object contains objects that define the configuration, user data, status and
command control data related to the module. Each of these object types is
discussed in the following topics of the document.
Configuration Objects
Configuration of the module is performed by filling in the values in the module
object defined in the Controller Tags Edit Tags dialog. Each parameter required
by the module has a defined location in the object. The tables and discussions
below describe the parameters set in the dialog box. You can view these tables
by opening the data type under the User Defined Data Type option in the
Controller Organization window.
Data Transfer Parameters (CASModule)
This object defines the parameters for data movement between the module and
the processor. Values entered determine the ladder logic and data size required
in the application. The ReadData and WriteData arrays must be sized to or larger
than the count values entered. The ladder logic must process the number of
blocks of data to be transferred. The number of blocks is computed as follows:
BlockCnt = INT(RegCnt/200) + if(MOD(RegCnt,200), 1,0)
If the register count is evenly divisible by 200, the number of blocks is easy to
compute and the ladder is much simpler to write. If the number is not evenly
divisible by 200, special handling of the last block of data must developed, as it
must transfer less than 200 words. It is recommended that the count values
always be set to values evenly divisible by 200.
ProSoft Technology, Inc.
December 26, 2007
MVI56-CAS ♦ ControlLogix Platform
Teledyne CA Slave Module
Page 25 of 86