Of timer in PLC equivalent to relays time relays in the system.
It has a set value registers (one word), a current values of registers (one word) and an image uses to store its output contact status register (binary bit), these three storage units using the same component number. FX series PLC timers are divided into general purpose timers and totalizer timer.
Constant k can be used as a timer value, can also use the data register (d) to set the timer. For example external digital switch inputs can be saved to the data register, as the timer value. Have battery backup data register is often used, so that when the power failure without losing data.
1. General purpose timers
The series timer number and component ID as shown in table 3–5. Timing of 100ms timer timing range for the 0.1~3276.7s,10ms timer range is 0.01~327.67s. FX1S special auxiliary relay M8028 is 1 when T32~T62 (31 points) was defined as 10ms timer. In Figure 3–10 X0 normally open contacts is switched on, the T200, the current value of the counter start at 0, to accumulate the 10ms clock pulse count. When the current value is equal to the set value of 414, the normally open contact of the timer switched on, normally closed contacts disconnect, the T200 output contact after the coil is driven 10msx414=4.14s. X0 normally open contacts after disconnection, the timer is reset, it‘s normally open disconnect, connect normally closed contacts, current value to 0.
If you need a timer loop “power“ action when the instantaneous contacts, timer coil in parallel an auxiliary relay coils, contacts and use it.
Universal timer does not maintain function in the input circuit is reset or power failure. FX series timers only
For coils “通電“ delayed action after contact, if you need to delay action after the input signal becomes OFF, you can use the circuit shown in Figure 3–1l.
2. Integrating timer
100ms totalizer timer timing range of T250~T255 to 0.1~3276.7s. X1 normally open contact is switched on (see Figure 3–12), T250, the current value of counter to cumulative count 100ms clock pulses. X1 normally open stops timed disconnect or power failure, current values remain unchanged. X1 normally open again on or when you power on again to continue regular, cumulative time (T1+T2) at 1055x100ms=105.5s, T250–contact action. Because integrating the coil power off the timer won’t reset, X2 normally open contact is needed to reset the T250.
3. Considerations for using timers
If used in routine or interrupt programs T192~T199 and T246~T249, when they END directive in modifying the current value of the timer. When the current timer value is equal to the set value, the output contact timer coil instructions or END instructions are carried out in action. If not using the timer, in special cases, the timer may not work properly. If the 1ms timer is used to interrupt the program and subroutine, in its current value reaches the set value, the contacts in the implementation of the action when the timer of the first coil instructions.
4. Timer precision
Timer accuracy and procedures relating to the Organization of, and if the contact of the timer before the coil, accuracy will be reduced. An average error of about 1.5 times times the scanning cycle. Minimum time minus the timing error for the input filter timer resolution, 1ms,10ms and 1ms,10ms and 100ms 100ms timer resolution respectively.
If the contact of the timer after the coil maximum timing error for the scanning cycle twice times coupled with input filter. If the contact of the timer before the coil maximum timing error for scan cycle with input filter 3 times times time.
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