GE VersaMax PLC, User Manual

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When power flow to the timer stops, the current value stops incrementing and is retained.
Output Q, if energized, will remain energized. When the function receives power flow
again, the current value again increments, beginning at the retained value. When reset R
receives power flow, the current value is set back to zero and output Q is de-energized
unless PV equals zero.
10.9.1.3 Example
In the example, a retentive on-delay timer is used to create a signal (%Q0011) that turns
on 8.0 seconds after %Q0010 turns on, and turns off when %Q0010 turns off.
CONST
+
00080
%Q0010 %Q0011
%Q0010
ONDTR
R
PV
%R0004
0.15
10.9.2 Timer and Counter Functions On Delay Timer
The On-Delay Timer (TMR) increments while it receives power flow and resets to zero
when power flow stops. Time may be counted in tenths of a second (the default
selection), hundredths of a second, or thousandths of a second. The range is 0 to +32,767
time units. The state of this timer is retentive on power failure; no automatic initialization
occurs at power-up.
Enable
Preset Value
TMR
PV
(Q)
Address-3 words
Current Value
TENTHS
When the On Delay Timer function receives power flow, the timer starts accumulating
time (Current Value). The Current Value is updated when it is encountered in the logic to
reflect the total elapsed time the timer has been enabled since it was last reset.
If multiple occurrences of the same timer with the same reference address are enabled
during a CPU sweep, the Current Values of the timers will be the same.
This update occurs as long as the enabling logic remains ON. When the current value
equals or exceeds the Preset Value PV, the function begins passing power flow to the
right. The timer continues accumulating time until the maximum value is reached. When
the enabling parameter transitions from ON to OFF, the timer stops accumulating time
and the Current Value is reset to zero.
Instruction Set Reference GFK-1503E User Manual 187
For public disclosure