User's Manual
The following figure shows an example of how a rail of National Instruments I/O modules can
be connected to DECT Messenger. On a rail, there can be various types of I/O modules. The
maximum number of modules for each rail is 8.
Important:
Although you can build configurations with many input or output modules, there is a limitation
on the number of input or output modules than an eIO DECT Messenger module instance
can handle. One eIO module can handle up to 8 input/output modules. So when you connect
a 9th module, even though it is recognized by National Instruments Measurement &
Automation Explorer, it cannot be handled by the eIO module.
Figure 4: Example of an I/O module connected to DECT Messenger
Note:
The maximum number of contacts per eIO Module in the DECT Messenger is 128.
If necessary, more than one rail can be connected to DECT Messenger. The following figure
shows an example configuration of three rails with National Instruments modules connected
to a DECT Messenger. The three rails with modules are connected together via the RS-485
bus.
National Instruments Analog/Digital Hardware
DECT Messenger Installation and Commissioning — Book 1 March 2012 21