VL-1225/6 Analog Input/Output Board
2-15
Current Loop Mode
While the VL-1225/6 cannot directly hook up to a 4-20 ma current loop, the addition of an external user-
supplied 500
W
precision dropping resistor can be used to develop a 2-10 volt signal proportional to the 4-
20 ma current. This voltage is applied to the VL-1225/6 as a differential-mode signal. The input range
should be jumpered for unipolar 0 to 10V operation. The circuit below can be repeated for all 8 differential
input channels.
Figure 2-14. Current Loop Input Mode
Configuration – Analog Input Configuration
