User manual

IEC61131 User and Reference Manual
April 22, 2008
372
units
Integer
Input Rate period
0 = second
1 = minute
2 = hour
3 = day
interval
Integer
The interval specifies the sample interval at which the rate
input will be sampled. A sample is taken and a calculation
performed if the time since the last sample is greater than
or equal to the sample interval. Valid values are 1 to
65535 tenths of a second.
Note: The period over which readings are taken will
vary, but will stay in the range –1 * (Expected Interval +
Configured Sample Interval + Maximum time between
ladder logic scans) <= Actual Sampling Interval <= +1 *
(Expected Interval + Configured Sample Interval +
Maximum time between ladder logic scans). As a result
the total for individual periods may fluctuate despite a
constant input.
period
Integer
Specified record to be displayed (1 to 35)
 The accumulated total does not change if the period is
changed.
 The accumulated total is set to zero if the period is
invalid.
Outputs
Type
Description
status
Integer
Status
0 = no error
1 = invalid ID
2 = invalid unit input
3 = invalid interval input
4 = invalid period input
5 = no memory available
total1
Real
total for period 1
end1
Integer
Time at end of period 1 in seconds since January 1, 1970
time1
Integer
Accumulation time for period 1 in seconds
totalP
Real
Total for period P
endP
Integer
Time at end of period P in seconds since January 1, 1970
timeP
Integer
Accumulation time for period P in seconds
Notes
The total function block stored data is retained when the program is stopped, power is cycled
or the controller is reset. The stored data is cleared when the controller is initialized or when
the enable input is OFF.
The accumulated value is a floating-point number. All floating-point numbers are
approximations. If the accumulated value grows large, then low rate inputs will have little or
no effect on the accumulated value and the accumulated value will not be accurate. Use the