User manual

Toolbox 32 User Manual 1.47d www.cse-semaphore.com/mykingfisher
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109
Example - Exception Reporting Analogs
Analog values can be exception reported to the master RTU when there has been a percentage change (of
the analog range) from the last reported value. This is done by using two registers, a constant and an analog
input. The constant is used to specify the amount the analog value must change by before an exception
report is generated. The registers are used to store the last reported value plus the constant and the last
reported value minus the constant. When the analog value moves above or below these register values, an
exception report is generated and the registers are updated.
The lower register limit must be checked if it is negative as a negative number is stored as a very large
integer value and can cause continuous exception reports as the low limit comparison block is always true.
The constant to use is calculated as percentage of the analog or register range. For analog inputs which
have a range of 0-32760 (32767 for an AI-10), a 1% change is represented in the RTU by a change of about
327. Similarly, a 5% change is represented in the RTU by a change of 1638 (0.05 x 32760).
│ │
├Monitor IO-4 AI Chs1&2 for 5% change. Ex. report to RTU1 ┤
│ │
│AI1>HiLimit Update RTU1 │
│ #AI14.2 #R100.2 │
├─────[>]─────────────────┬──────────────────────────────────────┬─────(S)─────┤
│ #R101 │ │ │
│AI1<LoLimit LoLimNegativ│ │UpdateHiLim │
│ #AI14.2 #R111.16 │ │┌ #R101 ┐│
├─────[<]──────────┤/├────┘ ┼ ┼ ├┤= #AI14.2 ├┤
│ #R111 │└+ 1638 ┘│
│ │UpdateLoLim │
│ │┌ #R111 ┐│
├ ┼ ┼ ┼ ┼ └┤= #AI14.2 ├┤
│ └- 1638 ┘│
│AI2>HiLimit Update RTU1 │
│ #AI14.3 #R100.2 │
├─────[>]─────────────────┬──────────────────────────────────────┬─────(S)─────┤
│ #R102 │ │ │
│AI2<LoLimit LoLimNegativ│ │UpdateHiLim │
│ #AI14.3 #R112.16 │ │┌ #R102 ┐│
├─────[<]──────────┤/├────┘ ┼ ┼ ├┤= #AI14.3 ├┤
│ #R112 │└+ 1638 ┘│
│ │UpdateLoLim │
│ │┌ #R112 ┐│
├ ┼ ┼ ┼ ┼ └┤= #AI14.3 ├┤
│ └- 1638 ┘│
│ │
Figure: Exception Reporting IO-4 Analog Channels 1 and 2.