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I would
agree with jerry.bradford. Its important
to differentiate between redundant communications (a feature of PACProject
Professional HW to enable the second Ethernet port) and redundant controllers,
where a secondary “standby” controller takes over control of the program if it
detects a failure in primary “running” controller.
While redundant
comms are handled by the operating system, the use of redundant controllers requires
the functionality to be developed as part of your application software under
PACControl.
This is the
same as many PLC’s that offer “redundancy”. Only a few high end models include controller
redundancy at the operating system level.
The rest depend on application software, examples of which are usually
supplied by the manufacturer. Maybe someone nice in Opto22 could develop an
example strategy for PAC hardware.
Use 2 PAC-S
controllers (S1 or S2) to talk through a switch to one or more SNAP-PAC-EB1 o
SNAP-PAC-EB2 brains. If you are
seriously implementing redundancy you should also consider the use of separate
power supplies for each SNAP-PAC-S controller and a diode arrangement for dual
5VDC power supplies for the PAC-EBx brains.
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