Monitor 4-20Ma Sensor Current Loop With Quick Talk Analog 7. Input - Ritron Quick Talk RQA-451 Owner's Manual

NOTE: With Input #2 in On/OFF mode, Quick Talk
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switch is open, Quick Talk
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(Quick Talk disabled), and it is then closed, Quick Talk
condition of Input #1.
M 4-20 A S
ONITOR M ENSOR
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Quick Talk can act as a current sink when a resistor is connected between an Input's positive and negative
connection. The resistance value is selected to scale the current to the permitted 0 - 5 Volt range for the Input to
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Quick Talk . The following formula is used to calculate the Analog Threshold Setpoints necessary for your
application.
Analog Threshold Setpoint = 4-20 ma current (Amps) times the resistor value (Ohms)
NOTE: A resistor value of 250Ω provides the maximum resolution, and is the recommended value. Using a lower
resistance value with the 4-20 mA current loop produces less than 5 V at the Input and the measurement resolution is
reduced. Using a higher resistance value at 20 mA can produce a voltage greater than 5V at the Input, which will not
be recognized.
To configure an Input for 4-20 mA current loop:
1. Connect a resistor between the two wires on the Quick Talk
desired Input (see Table 6)
2. Connect the output of the 4-20 mA current loop device to the positive (+) wire of the Input connection.
3. Program the desired Input for Analog Input operation and for the calculated Analog Setpoints.
4. Record an Input OPEN and Input CLOSED message for the associated Input.
For assistance, call RITRON at 800-872-1872, or go to
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functions normally with the external switch closed. When the
is disabled and will not transmit messages. When the On/Off switch has been open
C L Q
URRENT OOP WITH UICK
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transmits the prerecorded message describing the current
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T A I
ALK NALOG NPUT
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color-coded cable that are associated with the
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