What instruction increases its count value (CV) by one each time its count up (CU) input turns from false to true?

The instruction that increases its count value (CV) by one each time its count up (CU) input transitions from false to true is the Count Up (CTU) instruction. This behavior is fundamental to counting operations within programmable logic controllers (PLCs), where the CU input acts as a trigger. When the CU input signal rises from a low (false) state to a high (true) state, it indicates an event or occurrence that the system needs to count, thus incrementing the count value by one.

In the context of automation and IIoT, understanding the behavior of such counting instructions is crucial for applications like monitoring production cycles, tracking item counts, or enabling specific operations based on numerical thresholds. The Count Up instruction is pivotal for scenarios where a series of events need to be counted, facilitating effective data analysis and reporting in industrial environments.

Other options represent different functionalities: Count Down (CTD) decreases the count value; Reset Count (CTR) resets it back to zero; and Count Hold (CTH) keeps the current count value without incrementing or decrementing. Each of these serves distinct purposes in control systems, but they do not fulfill the requirement of increasing the count value with a positive edge signal, as the Count Up instruction