Fluke 787 - Manual (Page 29)

ProcessMeter™
Using the Current Output Functions
21
Using the Current Output Functions
The Meter provides steady, stepped, and ramped current
output for testing 0-20 mA and 4-20 mA current loops.
You can choose source mode, in which the Meter
supplies the current, or simulate mode, in which the Meter
regulates current in an externally-powered current loop.
Source Mode
Source mode is selected automatically by inserting the
test leads into the SOURCE
+ and − jacks as shown in
Figure 7. Use source mode whenever you need to supply
current into a passive circuit such as a current loop with
no loop supply. Source mode depletes the battery faster
than simulate mode, so use simulate mode whenever
possible.
The display looks the same in source and simulate
modes. The way to tell which mode is in use is to see
which pair of output jacks is in use.