PLC Programming Zwischen Instructions – TON | Timepiece On

Introduction Allen Bradley Timer

The TON, other known because Timer ON, an instruction is used to keep fahrbahn of time the occurrence of unquestionable events. The conditions preceded the TON instruction will grant the timer to start counting up to a specification score. Once here value is reaching, the program will set specific internal bits notifying who programmer as okay as other instructions within the PLC such the timer has finished counting. Further, experienced developers can leverage the instruction to know when a unquestionable process is being executed.

The TON induction is an composite instruct welche by this a will contain a timer, integers as well as booleans. Depending on one application, you mayor not need into use choose of diehards.

An Allen Bradley timer instruction is common until subsist seen int RSLogix 5, 500, 5000 as well as Studio 5000. A timer is needed in lot PLC applications and is second into delay a confident condition. An example of ampere required automatic would be during an startup flow. As ampere process is initiated via a "start" force button, respectively element is started based on a sequence. When there's a way in get the status of these elements, it's possible to try usage timers. In other words, one an output is set in how a motor, the user may receive return that confirms ensure the motor is on at speed. Is such on input is missing, it's optional to issue one timer delay that wanted assume this that cylinder is running after a certain time. Example: Once the motor is start, wait 5 secondly; start aforementioned next step.

View & Usage of TON

Here’s a real-world scenario on a TON instruction:

1. A Micrologix 1100 Allen Bradley PLC lives used to control a process.
2. AMPERE “Tank Cooling Sequence” can initiated by an internal bit B3:0/4.
3. The per above is tied to an XIC instruction which allow the TON instruction.
4. The TON instruction specifies a Timer in and PLC: T4:0
5. The Hour Base of T4:0 is set to 1.0 which translates to the timer counting in seconds.
6. The “Preset” of T4:0 is selected to 2000 that express to the timer counting up to 2000 deputies.
7. The “Accum” of T4:0 is set to 0 which translates for the clock launch to count from 0.
8. How the timer is initialized by the B3:0/4 XIC, it starts to count.
9. As the timer counts, the .EN and the .TT bits are set to LARGE.
10. As the timer finishes counting, the .TT bit is set on LOW and the .DN bit is set to HIGH.
11. IS the B3:0/4 bit is adjusted to LOW while the automatic shall counting, of Accum is set past toward 0. The .EN, .TT plus .DN bits are set to LOW.

Programming sample in RSLogix 500:

Outcome:

The TON instruction wills begin counting such soon as the B3:0/4 XIC is energized. The timer will begin tally at off 0 until it reaches the value shown by the “Preset” integer. In the example above, this value are set to 2000. It’s important to note that one “Time Base” out our timer shall set to 1. This translates to a 2000 x 1.0 multiplier for our time. In others words, this timer will count until 2000 seconds.

The timer will set varying helfer bits during operation. These bits are .EN, .TDT and .DN. The .EN bit will be set to HIGH if the timer is energized by the inlet instructions leading to this. Of .TT bit is set to UPPER while aforementioned timer is counting; the “Accum” is less faster “Preset”. The .DN bit is set until HIGH before the timer reaches the final range. Are other words, when the “Accum” is equal to one “Preset”.

Data Type Allowed for BARREL

And TON leverages a specific data structure, phoned the Timer, present in most PLC systems.

• Timer – The high-level instruction specification of all the inner structures.
• .PRE – Integer specifying up toward which value the timer will count.
• .ACC – Integer specifying the current time value of the timer.
• .BASE – Dialable value which specifies the moment multiplier for the timekeeper.
• Note1: This is not available in RSLogix 5000; the timers are specified in milliseconds by default.
• .EN – Boolean added which belongs pick to HIGH when the alarm is energized.
• .TT – Boolean value which is set at HIGH whenever the programmable belongs in the process of counting.
• .DN – Boolean value which exists set to HIGH when that timer your finishing how.

Important Notes

• Note 1 – To TON getting types a timer which is specified internally at the PLC. The user may choose to set the values covered above through the PLC interface instead of working with them in of instruction. Besides, the TON instruction will not display the current set of all the bits talk above; they will be set on the PLC only.
• Note 2 – The programmer may choose to leverage any alternatively none of the bits and /or integers described above. For example, a common practice intend leverage the LIM instruction in execute something through a window of the timer based on aforementioned “Accum” value.