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P
A
R
A
M
P
A
R
A
M
INPUT RANGE
SOURCE IMPEDANCE
ABSOLUTE LIMITS
15.2
All analog inputs are non-isolated. All analog measurements are referenced to GROUND. Take care
when connecting the DATAFLOW RTU to external sensors.
15.3
The user can invert the input state of a DATAFLOW RTU if desired, which will cause a DATAFLOW
RTU that reads an analog signal as full scale to transmit the signal status as a 0 scale to another
DATAFLOW RTU. This inversion allows a positive transfer function signal to control a negative transfer
function signal without external circuitry.
15.4
Sensor excitation voltage may be supplied by the DATAFLOW RTU using the J101 pin 5 Power Out
pin. For this configuration, make sure to not exceed the maximum current drive of the pin, and ascertain
your sensor will operate on a supply voltage of Vsupply-5Volts.
16.
A
N
A
L
O
G
O
U
T
P
U
T
S
A
N
A
L
O
G
O
U
T
P
U
T
16.1
The two analog outputs are defined to be pins 15 and 17. (NOTE: Pins 15 and 17 are outputs only if
PJ101 and PJ102 are configured as outputs.). These outputs are two low power outputs hardware
configured as either a voltage source or a current sink. All analog outputs are referenced to GROUND.
16.1.1
If the output pin is desired to be a voltage source, correctly set the hardware configuration. The pin is
to be hardware-configured as an output and as a voltage source. The following table defines the
characteristics of the output pin set as a voltage source. Attempting to drive a load less than the minimum
will cause incorrect output and possibly damage the device.
P
P
A
A
R
R
A
A
M
M
OUTPUT RANGE
LOAD RESISTANCE
16.1.2
If the output pin is desired to be a current sink, correctly set the hardware configuration. The pin is to
be hardware configured as an output and as a current source. The following table defines the characteristics
of the output pins set as a current sink. Attempting to drive a load less than the minimum will cause incorrect
output and possibly damage the device.
P
A
R
A
M
P
A
R
A
M
OUTPUT RANGE
LOAD RESISTANCE
16.2
The analog outputs can be programmed to have both initial and fail-safe conditions. The initial
condition forces the output to a desired state at power ON of the device. The fail-safe condition forces the
output to a desired state if a RF data link problem is detected. Refer to DATAFLOW RTU
Software/Programmers Manual for details on setting these conditions.
16.3
Meter excitation voltage may be provided by the DATAFLOW RTU using the Power Out pin 5 of
connector J101. If the Power Out pin is used as the excitation supply make sure that the maximum current
drive of the pin 5 is not exceeded and that your indicator will operate on a supply voltage of Vsupply-
5.5Volts.
16.4
It is not recommended to use the analog output as a warning indicator. If used, it is not available to be
mapped to the corresponding analog input of the other unit, meaning that a DATAFLOW RTU having an
analog output used in this manner can have only one analog signal sent to it. NOTE: Be sure to not exceed
the load drive capability if an analog output is used for a warning indicator.
17.
T
H
E
O
R
Y
O
F
O
P
E
R
T
H
E
O
R
Y
O
F
O
P
E
R
17.1
The DATAFLOW RTU control board performs many functions. It is used to program and control the
DTX RF board. It is the real-world interface for the telemetry inputs and outputs. It communicates to devices
E
T
E
R
E
T
E
R
S
E
E
T
T
E
E
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E
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E
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E
T
E
R
A
T
I
O
N
A
T
I
O
N
M
I
N
I
M
U
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M
I
N
I
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U
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0 mA
-8 mA
M
M
I
I
N
N
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U
U
M
M
0 V
1000 ohm
M
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N
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0 mA
8
M
A
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A
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20 mA
(Ev-5)/.02 ohm
28 mA
M
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A
A
X
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M
U
U
M
M
5 V
M
A
X
I
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U
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M
A
X
I
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U
M
20 mA
(Ev-5.5)/.02 ohm
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