Operation of PLC counter

 PLC counter 

The PLC counter has a programming format similar to the timer format. In this way, the input to the PLC counter is given as a pulse that counters a variable and is analyzed by the PLC. Other inputs are used as enable/ reset. Revolution counters are mainly used in all types of manufacturing industries depending on the movement of a product or machine. The PLC counter provides separate inputs for enable and reset, which are used according to the manufacturing process. The PLC counters are connected to mechanical, electrical and electronic functions which are replaced through a conventional counters. Counters are used to count the speed and parts etc. of a machine. 

PLC counters mainly count products and packets or cartons in an industry. Counting in this is accomplished by a certain programming in which different types of sensors, solenoid valves, and other types of sensing instruments are used. 

Counter Parameters - 

The position of a number is increased or decreased by the counter parameter which is given a fixed path by the counter. The PLC counter mainly consists of two parameters which are as follows - 

1. Accumulator Parameters - Accumulator value in accumulator parameter ranges from false to true, in zion.  In this, it is generated when the counter is preset to a value. 
2. Preset Parameters - The preset parameter value is displayed from the PRE.  In this, the space value is passed to the counter so that the controller sets the dun bit.  This status is set when the accumulator value is greater than or larger than the preset value.  It is used to control the output device.                                                           The counter ranges of the preset and accumulative values ​​range from -32,768 to +32,767 which is stored in the sign integer and the negative value is stored in the form of 2's complement.

PLC Counter operation 

Counter instruction in PLC operates just like timer instruction. The difference between a timer and a counter is that the timer instruction continuously increases the accumulated value, then the enabled contact is turned on. In other ways, the counter increases the entire contact traction accumulative value in the form of 0 and 1. This means that the contact returns to its position as 0, allowing it to repeat the transition. Contact traction in the counter can be stopped at any time. In this, what is important in place of transition is used in the counter. The diagram shows the counter's instructions with a preset operation.  

Counter operation

The counter has preset and accumulative values ​​similar to the timer. The preset value is the derived value for the counter that is used to count more values ​​as needed. The maximum preset value for the counter is 9999. The counter performs several control operations between this value. When the accumulator value is equal to the preset value, then its status bit is high. Its status Vit controls all the normal open and normal close contacts in which all the numbers in the counter are the same. The counter also maintains a similar type of vit that indicates whether the counter is in the overflow state or in the underflow state. When the counter is in the overflow state, the accumulator is at 9999 and when it is in the underflow state it is at 0. The overflow and the underflow condition set the same bit in the counter. 50 is added to the counter to get the address. For example, if the counter address is 902 and any contact is controlled by the overflow bit, then its address is 952 
The counter has a preset instruction like the timer used to counter the PR value. Its preset value starts at zero when the up counter instruction is used and its preset value ends at zero when the down counter instruction is used. In this way, when the status bit is energized, its preset value will be equal to the accumulator value and its accumulator value will be equal to zero for the down counter 

PLC  Counter Type  

1. Up Counter - Most up counters are used in operations.  A certain operation is counted by an up counter.  Counter operation is used at a fixed location and for a fixed function.  This counter is used to count more than one item                       Example, in a packaging plant, a carton has 12 cans.  In this way, each count is placed inside a can carton in which a number is incremented.  When Kane reaches the carton, the counter sends a message to the processor that the carton is full.  In this way the processor activates the other device.  This device seals the carton and moves it towards the assembly line. 
2. Down Counter - Down counters are also used like up counters.  With this, a certain function is performed.  In this, the count number is reduced.        Example, in the juice can packaging plant of the inventory control system, if it has a high amount of empty cans, it is down counted by a certain operation and the counter sends a message to the processor that the number of empty cans is high. In this way these canes are sent to the assembly line to be replenished. 
3. Up- Down Counter - Up-down counters are a mixed form of up and down counters.  Often the down counters are not used alone.  It is used with up counters.  These counters are mainly used in inventory control in which products are either entered into the assembly line or released.  These counters are also called trek defector parts.                                                        Example, if 10 parts are shown on the assembly line by a down counter, then 8 parts are removed from the assembly line by the up counters.  Which consists of 2 defective parts