Measurement Computing CIO-DAS48-I - Manual (Page 14)

CIO-DAS48-I User's Guide Functional Details
14
Three-wire devices
Figure 9 shows a three-wire, 4 to 20 mA device connected to channel 0 of the CIO-DAS48-I. Three-wire
devices will typically specify the maximum load resistance for the current output. The input resistance of the
CIO-DAS48-Iis 100 Ω (determined by the CIO-DAS48-ISIP installed). Add this value to any other load
resistances in the loop. Typically, the maximum resistance specified for three-wire devices is on the order of
1 kΩ
CH 0 IN HI
CH 0 IN LO
100
3-wire,
4 - 20 mA
Device
CH 0
LLGND
CIO-DAS48-I
+ 24V
Figure 9. Connecting a three-wire device