Components and Architecture - Components 
14   HC900 Process Controller Installation and User Guide  Revision 19 
    06/14 
 
 
 
Figure 4 – Configuration with Multiple Controllers 
 
CAUTION 
The HC900-expansion I/O link is a private network and the switch used for the interconnection of 
the HC900 Processor and Scanners must not be connected to any other LAN or WAN.  Likewise, 
no devices other than the HC900 components should be connected to the I/O link Switch.  Failure 
to comply will cause communication failures on the I/O link causing I/O modules to go in and out 
of their failsafe settings.