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Signet 8900 Multi-Parameter
11.2 Multiple Relay Sources and Advanced Relay Mode
When a Relay Source is set to "MULTIPLE" and the Relay Mode is set to "Advanced", the relay can be activated by up to three different
conditions. ADVANCED mode presents four Boolean logic formulae called "Relay Operators." Each Operator can be programmed with
up to three different conditions. The relay will only be activated when the complete formula is satisfi ed.
•
A TRUE condition means that the parameter is beyond the setpoint.
•
A FALSE condition means that the parameter is within the setpoint.
•
If any one of the three conditions shows "CHK SENSOR" then that condition will be treated as always FALSE.
(a l b l c)
means
"Activate this relay when either
a OR b OR c is true."
(a & b & c)
means
"Activate this relay only when
a AND b AND c are all true."
(a l (b & c) )
means
"Activate this relay if a is true
OR if b AND c are both true."
(a & (b l c) )
means
"Activate this relay only if a is true
AND either b or c are also true."
Boolean Relay Logic Operations
Program a Relay for Advanced Operation
Relay 1 Operator
( a | b | c ) >
Relay 1 Operator:
( a & b & c ) >
Relay 1 Operator:
( a |(b & c) ) >
Relay 1 Operator:
( a &(b | c) ) >
Example: Set Relay #1 to activate IF pH3 falls below 5, OR if pH4 rises above 8.5, OR if Level L6 rises above 18 inches. Relay #1 will
activate 30 seconds after any one the conditions are met.
Condition a:
The pH on Channel 3 is less than 5.
Condition b:
The pH on Channel 4 is greater than 8.5
Condition c:
The Level on Channel 6 is greater than 18.
When operating properly, all three of these conditions are FALSE. If any one of them becomes TRUE, then Relay 1 will be activated.
Relay 1 will remain activated until the TRUE condition becomes FALSE again, including the hysteresis band.
Relay 1 Source2:
pH4 >
Relay 1 Mode 2:
High >
Relay 1 Setpnt2:
8.50 pH >
Relay 1 Hys 2:
0.5 pH >
Relay 1 Source3:
Level L6 >
Relay 1 Mode 3:
High >
Relay 1 Setpnt3:
+18.00 in >
Relay 1 Hys 3:
1.00 in >
Relay 1 Source:
Flow F1 >
Relay 1 Source:
Multiple >
Relay 1 Mode:
Advanced >
Relay 1 Operator
( a | b | c ) >
Relay 1 Source1:
pH3 >
Relay 1 Mode 1:
Low >
Relay 1 Setpnt1:
5.00 pH >
Relay 1 Hys 1:
0.5 pH >
Relay 1 Delay:
30.00 secs >
2.
Use the keypad to navigate through the Relay menu. Set the relay Source to "Multiple" and set the
Relay mode to "Advanced."
3.
Select the Relay Operator that represents the set of conditions.
In this example that is (a | b | c).
4.
Set up to three sources for the Relay, assign a
Mode to each source (High, Low or Off)
Set a Setpoint and Hysteresis for each source.
5.
Set a relay delay time if applicable.
When all relay parameters are set, press the UP and DOWN keys together to exit from the Relay menu back to the Menu Directory,
then press the same keys again to exit from the Menu Directory back to normal operation.
1.
Starting from normal operation (View mode), Press and hold the ENTER key for 2 seconds to jump
to the Menu Directory. Press the DOWN key three times to scroll to the RELAY menu then press
ENTER key.
