I recently created my very first function block routine using the CLX L72 v24I, specifically a totalizer that was requested by our engineering team. Thanks to the support from this forum, the totalizer is functioning excellently! The next objective is to configure Ignition to automatically log the totals to a database on a daily basis. My plan is to have Ignition reset the totalizer after capturing the current total. Reading the total is straightforward; however, I'm seeking the most effective method to reset the totalizer. One option is for Ignition to trigger the totalizer's reset bit. But how can I ensure the total resets to zero (0) once the current total has been transferred to the 'old total' tag? In ladder logic, I would use a condition to unlatch the bit (U). What would be the equivalent operation in Function Block Diagram (FBD) for unlatching? Alternatively, are there more efficient methods to achieve this?
If I were in your position, I would create an array called MyArray[32] to effectively handle data transfer via the PLC (Programmable Logic Controller). This approach utilizes your data pointer based on the day of the month, providing a month's worth of data as a reliable buffer. While I am not familiar with Ignition software, let's assume it’s configured to log data at midnight (00:00) each day. I recommend setting up Ignition to activate a specific bit once the logging is complete. When this bit is set, the PLC can then transfer the current total into the array and reset the totalizer. To ensure data integrity, if the logged bit isn’t received by approximately 00:02, the PLC should still carry out the data transfer. Additionally, you might consider implementing an alarm system to alert you if the log hasn't been recorded. This strategy will create a robust buffer within the PLC in case the log fails, allowing for data retention over a few days without being noticed, along with immediate notifications if a logging issue arises.
It's great to hear that your totalizer is working well! For resetting the totalizer in FBD after you've logged the current total, you can use a "Rising Edge" detection or a "One-shot" block after you transfer the total to the 'old total' tag. Essentially, you can trigger the reset bit based on the condition that your logging action is complete; once that condition is met, you would set the reset bit high for just one cycle, effectively unlatching the reset. This method helps ensure that you’re not accidentally resetting the totalizer before the log action is finished. Another approach could be to integrate a state machine that tracks the steps, so you have clear control over when to reset in relation to your logging process. Good luck with your implementation!
It sounds like you’re making great progress with your function block routine! To reset the totalizer in FBD, you can use a combination of a "Set" and "Reset" block with a latch condition that checks if your current total has been successfully logged. After transferring the total to your 'old total' tag, you can use a Boolean condition, like an AND block that evaluates if the logging was successful before sending a pulse to the Reset block. This way, you won’t be inadvertently resetting the totalizer until you know the data is stored, making your process safer and more reliable. Let me know if you need specifics on the blocks!
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Answer: A1: To reset a totalizer in a Function Block Diagram (FBD) using the CLX L72 v24I, you can use a reset bit. You need to ensure that the reset operation occurs after transferring the current total to an 'old total' tag. This can be managed by setting a condition in the FBD that resets the totalizer when the reset bit is triggered by your control system, such as Ignition.
Answer: A2: In Ladder Logic, you use an unlatch (U) instruction to reset a bit. In a Function Block Diagram, you can achieve a similar result by using a reset coil or a reset instruction. This typically involves setting a condition that, when met, will reset the totalizer value to zero.
Answer: A3: To integrate Ignition for automatically resetting the totalizer, you can set up Ignition to trigger a reset bit in the control system after it has logged the current total to a database. This involves configuring Ignition to communicate with your PLC and
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