User manual

Toolbox 32 User Manual 1.47d www.cse-semaphore.com/mykingfisher
Page
206
Example
The example below shows how to changeover the CPUs if the duty CPU's real-time clock fails. The ladder
logic is also used to display the state of the duty CPU (#R100.8) and the standby CPU (#R100.9).
│ │
├Changeover CPUs if the clock fails ┼ ┼ ┤
│ │
│ClockFail Ch'overCPUs │
│ #YDIAG.4 #YEXCEP │
├──[UP-EDGE]─────────────────────────────────────────────────────────(Copy)────┤
│ 16#800 │
│ │
│ │
├Monitor CPU modules (RTU Layout: PS-11,PS-11,CP-11,CP-11) ┤
│ │
│CPUWatchDog Clock Fail RAM Fault Duty CPU OK │
│ #YDIAG.15 #YDIAG.4 #YSTAT.16 #R100.8 │
├─────┤/├──────────┤/├──────────┤/├────────────────────────────────────( )─────┤
│ │
│CPU Slot 3 IOBUS Fail CMBUS Fail StandbyCPUOK │
│ #YMTYPE3 #YEXCEP #YEXCEP #R100.9 │
├─────[=]──────────[!]──────────[!]────────────────────────────────────( )─────┤
│ 29 16#600 16#700 │
Figure: Redundant CPUs ladder logic
Redundant Power Supplies
Two or more PS-xx power supplies can be plugged into a backplane in any available slots. Each power
supply will run normally, sharing the power load (equal load sharing is not guaranteed). If one power supply
is removed or fails, the other power supplies will supply the complete power load. Ladder logic is not
required when using two of these power supplies on the one backplane.
When two or more power supplies are present on the backplane, one power supply can be hot swapped
while the RTU is still running. This does not cause any interruption to the processor or inputs and outputs.
To determine the Total Current supplied by both power supplies to the RTU modules and batteries, the
current load for each power supply (#AIss.4) is read and the figures are totalled.
Note: if two or more power supplies are present on the backplane and one is switched off, the Radio, 24V
Auxiliary and Battery outputs will still be active on the power supply that is switched off. The Radio and 24V
Auxiliary outputs on each power supply can be controlled using ladder logic.
Redundant Communications
It is possible to change the port and/or communications path used to communicate with a remote RTU if
there is a communications fail.
The first example below shows how to automatically change which RTU port is used. The second example
shows how to automatically change which network path is used.
For both examples the following will happen,
• The RTU initially uses the primary link and if there is a communications failure it switches to the
secondary link.
• While using the primary link, the secondary link is tested every 10 minutes.
• When using the secondary link, the primary link is tested every 10 minutes or immediately after the
secondary link fails.
• If the primary link is still bad, the network link reverts back to the secondary link.
• If both links fail, the RTU will alternate between the two links every 10 minutes.
#R20.1 is used to show comms fail for the primary link and #R20.2 is used to show comms fail for the
secondary link. The comms status for each link is only updated after a message has been sent via that link.
Note: to force a CP-10/11 to close its existing Ethernet socket and use the new network link settings, please
see the Network Link register
#YLSTrrr.11.