Ritron DATAFLOW RTU Technical Manual page 46

8.2.3.3 The FAIL-SAFE STATE table controls RTU outputs when the RTU detects a loss
of RF link. Because Example 1 has only one entry in the SEND UST of each RTU, only
FAIL-SAFE STATE A is used. IfRTUID 1 detects loss of RF link, RTUID I outputs are
controlled according to its FAIL-SAFE STA TE A; if RTU ID 2 detects loss of RF link,
RTU ID 2 outputs are controlled according to its FAIL-SAFE STATE A.
8.2.3.3.1 The loss of RF link is detected by a RTU according to the following process: After
a RTU transmits a message, it waits for acknowledge.
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If acknowledge is received, the RF link is good and the process ends.
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If acknowledge is not received, the RTU retransmits the message, repeating the
sequence until reaching the maximum number of retransmit attempts. The process
ends with the RTU detecting Joss of RF if the last (maximum number) retransmit is
made with no acknowledge being received.
8.2.3.4 I/0 CONFJG is Input/ Output control of the RTU displayed in the Programming
Software I/0 configuration screen. Examine the following items for Example 1:
8.2.3.4.1 Inputs l and 2 are configured to be inverted digital inputs.
Set digital inputs lNVERT to YES to make an open digital input produce an
NOTES:
open relay output and a closed digital input produce a closed relay output.
Set the INVERT for analog inputs 3 and 4 to NO to produce a positive
transfer function on an output.
8.2.3.4.2 All four outputs are used. The initial condition - the state an output is forced to
upon power-on - is set for rel ays to be open and analog outputs to be forced to O scale.
8.2.3.4.3 FROM ID is the transmitting RTU ID number; FROM ID numbers are listed in the
following chart:
8.2.3.4.4 FROM LOC is the number of the input that controls the output; FROM LOC
numbers are listed in the following chart:
Software/ Programm
AnaloaO•
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EXAMPLE 1
FROMID
IRTIJ ID#)
RTU ID 1 2
1
RTU 1D2
FROMLOC
!INPUT#\
Dinital Ou out 1
Diaital O••
ut2
0
nut 1
nut 2
AnaloaO•
(continued/
1
2
3
4
( B-16)