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Example 2: Transmit relay closing time in msec with 0.001 msec resolution
Application:
Transmit closing time of a relay in msec with 0.001 msec resolution using stop-
watch mode. Also transmit relay closing time from 0 to 200 msec as a 4-20 mA signal.
Solution:
•
As shown under Common Jumper Settings (page 17), set Channel A to “Logic levels” and
Channel B to “NPN open collector.”
•
Use Channel A to sense a positive voltage applied to relay coil. Wire Channel B across relay
contacts. Upon contact closure, Channel B pull-up voltage will drop from 5V to 0V.
•
Under Input+Display tab, set Mode to Stopwatch, Function to “A to B”, and Gate time to 0
sec. Set Display Type to “Norml 999999”. Native counts will be microseconds.
•
Under Scaling tab, set decimal point to 3 places. Set Trigger Slope A to Positive and Trigger
Slope B to Negative. If “Scale, Offset” is selected as scaling method, set Scale to +1.00000
and Multiplier 1 to read in units of 0.001 msec (or native microseconds). If “Coordinates” is
selected as scaling method, set High In to +010000 and High Read to +010.000. Or select a
similar pair of numbers which reflect a slope of 1. Ignore Item 2, “Grand Total Time”.
•
Under Analog Out tab, set Range to “4-20mA Current”, Lo Range Reading to +000.000 and
Hi Range Reading to +200.000.