DL205 Analog Manual, 7th Edition Rev. D
4-7
Chapter 4: F2-08AD-1, 8-Channel Analog Current Input
1
2
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14
A
B
C
D
1
2
3
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5
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7
8
9
10
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A
b
C
D
Current Loop Transmitter Impedance
Standard 4–20 mA transmitters and transducers can operate from a wide variety of power
supplies. Not all transmitters are alike and the manufacturers often specify a minimum loop
or load resistance that must be used with the transmitter.
The F2-08AD-1 provides 250
q
resistance for each channel. If the transmitter being used
requires a load resistance below 250
q
, it will not be necessary to make any adjustments.
However, if the transmitter requires a load resistance higher than 250
q
, a resistor will need
to be added in series with the input.
Consider the following example for a transmitter being operated from a 30 VDC supply
with a recommended load resistance of 750
q
. Since the module has a 250
q
resistor, an
additional resistor needs to be added.
0V
+30V
DC Supply
Two-wire Transmitter
+
--
Module Channel 1
R
250
ohms
CH1--
0V
CH1+
R = Tr - Mr
R - Resistor to add
R = 750 - 250
Tr - Transmitter Requirement
R
M
500
Mr - Module resistance (internal 250
q
)
Summary of Contents for DL205
Page 1: ...DL205 Analog I O Manual Manual Number D2 ANLG M ...
Page 2: ...Notes ...
Page 6: ...Notes ...