Under the processor status tab-> click PII then press 'F1' for help file
It shows
PLC5 PII Status Overview
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Tip
Interrogate the status file when the processor faults to determine the cause of the error. A quick method to call the status file when the processor has faulted is to click the drop-down arrow to the right of the Operational mode list box in the online bar. Then click Goto Error
The PII tab allows you to monitor configured settings for a processor input interrupt.
Fields on this display that are in gray are read-only. Fields shown in white are read/write. However, this information is seldom written to by the user program or programming device (unless you want to reset or clear a function). If you write to status file data, make sure that you first understand the function fully.
This information appears on the PII tab with the Structured Radix selected.
Access this dialog by double-clicking the Processor Status icon in the project tree or double-clicking the status (S2) file. Then select the PII tab to give it focus.
Click here for a list of the fields on the dialog and their definitions.
PII Status Parameter
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What's on the dialog?
Preset S:50
This field contains a value that determines how many conditions you want to occur before the interrupt. The valid range is 0-32767. A zero or a one in this field means the interrupt will occur every time.
Events since Last Interrupt S:52
This field contains the number of PII events (the input conditions that caused the interrupt) since the last interrupt.
File Number S:46
This field contains the number of the program file that contains the PII program.
Module Group S:47
This field contains the assigned rack number and I/O group number of the input to monitor (for example 21 represents rack 2, group 1). This is valid only for inputs in the processor-resident chassis. If the input word number specified is not in the local rack or if there is not an input module in the slot addressed, a minor fault bit (S:10/11) is set at mode transition.
Bit Mask S:48
This field contains a decimal number representing the bit mask for each module group bit (specified in S:47 above). In structured mode this will be a number between 0-32767. To better see or change the masked bits, view this tab in binary mode. Enter a 1 to monitor the bit. Enter a 0 to ignore the bit.
Compare Value S:49
This field contains a decimal number representing the compare value for each module group (specified in S:47 above). Bits in this word are used to control a PII through bit transition. To better see or change the transition bits, view this tab in binary mode. Enter a 1 for a trigger to occur on the false-to-true transition. Enter a 0 for a trigger to occur on the true-to-false transition. (In structured mode this will be a number between 0-32767.)
PII Changed Bits S:51
This field displays the bit transitions that caused the interrupt. You can use this information to condition other rungs in your ladder program.
If one of these bits is already set (i.e., a previous interrupt set the bit), the processor sets a minor fault (S:10/12) to indicate a possible PII overlap. If you want to monitor this overlap, make sure the last rung in your PII program clears this return mask in the status file.
Last Scan Time [x1 ms] S:55
This field contains the time it took for the current or last scan of the PII.
Max Observed Scan Time [x1 ms] S:56
This field contains the longest time that was ever displayed in the Last Scan field for a specific PII.
Warning:
Word not in Local Rack S:10/11
This field is checked if the input word number specified is not in the local rack or if there is not an input module in the slot addressed (S:47).
No Command Blocks S:10/13
This box is checked if no command blocks exist to get the Processor Input Interrupt. You can use the processor's internal counter or bit transition to execute the PII.
User Routine Overlap S:10/12
This box is checked if a set condition exists in the PII return mask or accumulator bits (possibly set by a previous interrupt) before completing the currently executing PII interrupt routine. PII return mask changed bits (S:51) are retentive. It may be necessary to place a MOV instruction on the last rung in the PII file. Move 0 in S:51 to reset the PII bits before finishing the PII file. If this is not done, a PII overlap bit will be set on that status page, causing this minor fault.
Rockwell Software Inc., 1997, 1998, 1999, 2000
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Basically you need to create a new ladder file say Ladder_30, define the ladder file in the Processor status window + define the inputs to be interrupted with the right bit mask.
So for a changed input status, the status bits will be changed in the processor. Say your input is tied to Input 0, then the addressing in ladder 30 for that input will be S:51/0. Use this to trigger/count what ever you want in the ladder.
If you are using this bit to count, add a non conditional rung above the counter to unlatch the counter/count up bit (eg: OTU C5:0/CU).
Hope this helps
