Watlow Series 942 - Manual (Page 10)

Install and Wire, Chapter 2
10 WATLOW Series 942 User's Manual
Input Wiring
Figure 10 -
0 - 5VDC Process
Input Wiring.
NOTE:
When using a
4 - 20mA process
input, the input
impedance is 249
Ω
.
NOTE:
When using a
0 - 5VDC process
input, the input
impedance is
100K
Ω
.
Figure 11 -
4 - 20mA Process
Input Wiring.
1
2
3
+
-
DC
I
4 - 20mA Process Input
Model # 942A - 2 _ _ _ - _ 000 942A - 3 _ _ _ - _ 000
A jumper must be
installed between
Terminals #2 and 3.
0 - 5VDC Process Input
Model # 942A - 2 _ _ _ - _ 000 942A - 3 _ _ _ - _ 000
1
2
3
+
-
V
DC
When using a process input such as 0 - 5VDC or 4 - 20mA, the rL and rH settings scale the
display to match the measured range of the process signal.
An example of this is: A pressure transducer operates over a range of 0 - 300 PSI, delivering
a 4 - 20mA output signal for this range. By setting rL = 0 and rH = 300, the Series 942 now
displays a direct reading of pressure.