User Manual v1.9
Manual
WI-I/O 9-K
v1.9
Page 21
Digital input
Update time, off state
1 day
Update time, on state
15 minutes
Input is expected to be on twice per year for 4 hours
No. of change messages per year
=
2 (twice per year) * 2 (on to off and off to on)
=
4
No. of “off” update messages per year
=
364 (approximately)
No. of “on” update messages per year
=
2 (twice per year) * 16 (4 hours @ 15 min update)
=
32
Total messages for digital input
=
4 + 364 + 32
=
400
Pulse input
Update time
1 day
Sensitivity 50
Average pulse rate is 1 pulse per hour, with peak rate of 20 per hour, for 10 hours, three times per year.
No. of change messages (normal rate)
=
0 (time for 50 pulses is more than the update time)
No. of change messages (peak rate) =
3 (three per year) * 200 (20 per hr for 10 hrs) / 50
=
12
No. of update messages per year
=
363 (approx)
Total messages for pulse input
=
12 + 363
=
375
Analog input
Sample time 1 hour
Warm-up time 5 secs
Sensitivity
3%
Update time 1 day
Average changes of >3% is twice per day
No. of change messages per year
=
2 (twice per day) * 365
=
730
No. of update messages per year
=
0 (always be a change message each 1 day)
Total messages for analog input
=
730
Total input messages per year
=
400 + 375 + 730 =
1505
Power consumed in transmissions
=
0.005 * 1505 * 2 (2 transmissions per message)
=
15 mAHr per year
Power for analog loop supply
(assume average loop current is 12mA)
No. of analog measurements per year
=
365 days * 24 hours * 1(sample time)
=
8,760
Power for analog loop supply
=
0.012 (from above table) * 5 (warm-up time) * 8,760
=
526 mAHr per year
