Emerson 2400S User Manual

Page of 50
Installation Manual
19
I/O Wiring – Model 2400S Analog Transmitters
P
o
wer Su
ppl
y
I/O
 W
irin
g
 – DP 
an
DN
I/
O W
iri
n
g
 – AN
Be
fo
re
 Y
o
Begin
Figure 3-12
Recommended pull-up resistor versus supply voltage – External power
3.4.4
Discrete input wiring
Discrete input wiring depends on whether you will use internal or external power. The following 
diagrams are examples of proper wiring for these configurations:
If external power is configured, power may be supplied by a PLC or other device, or by direct DC 
input. See Table 3-2 for input voltage ranges.
Table 3-2
Input voltage ranges for external power
VDC
Range
3–36
High level
0–0.8
Low level
0.8–3
Undefined
6
400
800
1200
1600
2000
2400
2800
3200
3600
4000
4400
4800
5200
12
18
24
30
36
Supply voltage (Volts)
Exter
nal
 p
u
ll-u
p
 re
sisto
r range
 (Ohms)
Recommended 
resistor value range
Note: When using a discrete output to drive a relay, choose external pull-up to limit current to 
less than 500 mA.