Rockwell Automation 1788-CN2FF ControlNet-to-FOUNDATION Fieldbus H1 Linking Device User Manual User Manual

Page 35

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1788-6.5.1 - January 1999

Using the ControlNet-to-FOUNDATION Fieldbus H1 Linking Device

4-9

The linking device contains a number of MDI block instances. Each
instance of the MDI block is the software equivalent of a discrete input
module in a I/O subsystem. Each MDI block has eight channels, with each
channel containing a byte and a status pair. The linking device assigns a tag
to each MDI block in the form CNetMacId

xx_DI_Modulei-j, where xx is

the ControlNet network address,

i is the Fieldbus channel number, and j is

the module or instance number.

Configuration of Discrete Inputs

The NI-FBUS Configurator lists all the devices and the function blocks in
each device in its browse window. This includes the DI function blocks in
the Fieldbus devices and the MDI function blocks in the linking device. You
must connect the Fieldbus DI function blocks that will be accessed by the
ControlNet controllers (or devices) to the MDI channels as shown in Figure
4.7. The remaining configuration is similar to that for the analog inputs.

Figure 4.7 Sample Single Macrocycle MDI Configuration

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