That screenshot of the Event Drum brings back some memories!
It's been a few years since I did any programming with the TI's, but I've only ever used the DOS based TISOFT. We never bothered with any of the Windows based offerings at the time. The last version I remember using was TISOFT 6.3.
The Timer/Event Drum simulates an electromechanical Drum Sequencer, or Cam Timer. In my experience, it was used more for complex state machines, or closed loop process control, but it can be used for simpler sequence driven logic.
It has 16 TIME or EVENT, or TIME and EVENT STEPS and 15 Outputs. Each of the 16 STEPS can turn any combination of the 15 Outputs ON or OFF as required. In your screenshot I can only see up to STEP 10, but all those 10 STEPS are used i.e. parameterized. Unless programmed otherwise, the EDRUM executes all 16 STEPS sequentially each time it runs. Also, there are only 6 of the 15 Outputs in use, C1008 - C1013. MASK values for unused Outputs are ignored as they are defined as C0000, which is an unusable address.
In your example, there are 2 FLAG Inputs to the EDRUM. C1007 should be the START FLAG, and C1000 should be the ENABLE/RESET FLAG. You need C1000 ENABLE/RESET ON before C1007 can START the EDRUM.
The PRESET parameter is set to 1, so the when the EDRUM STARTS, it begins at STEP 1. STEP 1 does not have an EVENT FLAG assigned, but does have a COUNT (CNT) value of 1. If you'll notice the SEC/CNT parameter is set to 0.100 (100ms), whereas the default is .001 (1ms). So a 100ms timebase was intentionally set here for the EDRUM. This is the time base which each STEP counts down from, according to its CNT value. A CNT value of 0, with no EVENT FLAG, means the STEP will advance to the next STEP immediately. So when the EDRUM STARTS at the PRESET STEP 1, it counts down 1 times the time base = 1 x 100ms, as does STEP 2 and STEP 3. So by the time the EDRUM reaches STEP 4, 300ms has elapsed. None of STEPS 1-3 turn any of the 6 Outputs ON, but they do set them all OFF, as they have a value of 0 in the MASK. This acts as a primer to set all the Outputs OFF before commencing the sequence proper. It then advances to the next STEP...
STEP 4 is EVENT driven only, as it has a FLAG assigned, C1027, but does not have a CNT value. So this means as soon as the FLAG C1027 is ON, STEP 4 sets C1010 ON, as it has a value of 1 in the MASK, and sets all the other Outputs OFF, as they have a value of 0 in the MASK. It then advances to the next STEP...
STEP 5 is also EVENT driven only. So as soon as Input X21 is ON, it sets C1012 to ON, but now sets C1010 to OFF, along with the other 0 value Outputs in the MASK. It then advances to the next STEP...
STEP 6 is TIME driven only. Here a CNT value of 5 gives a delay of 500ms, or 0.5sec (5 x 100ms). Then it sets C1009 and C1013 ON. It also sets the other Outputs OFF according to the MASK. This STEP acts as a half second de-bounce time for the Input X21 that came on in STEP 5. It then advances to the next STEP...
STEP 7 is similar to STEP 5, except it does not have a de-bounce time included it its own STEP, or in the next STEP. As soon as Input X20 is ON, C1009 and C1013 are maintained ON from the last STEP, but also it now brings ON C1011. It then advances to the next STEP...
STEP 9 and 10 are both 100ms delays, which maintain C1009 yet again, but set C1013 OFF. What happens after that I can't be sure without seeing STEPS 11 to 16.
When the EDRUM finishes STEP 16, the EDRUM Output, C1023, is set ON. This is usually used, among other things, to reset the sequence, or enable the next sequence in a larger sequence.
Note 1: When I say a STEP sets an Output OFF, or indeed ON, I mean it writes a 0 or a 1 to that memory address location. The program logic external to the EDRUM may write the same value, or an opposite value to the same memory address location. It's important to remember that the EDRUM is writing values of 0 and 1 to addresses, according to the MASK, and not just the values of 1 that you see. You can use the EDRUM to maintain the required state, such as your C1009 FLAG, or it can be done externally. In the case of C1012, which is enabled by X21. If this is the only place these addresses are directly used with each other, then C1012 will always be ON when STEP 5 is active, and always be OFF when it's inactive. Were you to program X21 on a rung directly to C1012, then, scan sequence aside, when the Input is ON, C1012 will always be ON, regardless of the STEPS in the EDRUM.
Note 2: If the ENABLE/RESET FLAG, C1000, and the START FLAG, C1007, are both ON and the EDRUM is running, and the ENABLE/RESET FLAG goes OFF. Then the EDRUM Output, C1023, is set OFF and the STEP is RESET to the PRESET STEP 1, waiting to be re-enabled. However, if the ENABLE/RESET FLAG remains ON while the START FLAG goes OFF, then the EDRUM pauses at the STEP it was at when the START FLAG went OFF. It will wait there until the START FLAG comes back ON, and resume, or the ENABLE/RESET goes OFF and the EDRUM RESETS. Check the logic that controls C1007 and C1000 for a possible pause feature that may have been used. Another possibility is that one of the Input FLAGS could be a JOG Input, used to increment the STEPS manually.
It shouldn't be too difficult to translate this logic over to AB, once you've figured out the sequence. It's basically a state machine.
Out of curiosity, are you converting to an RSLogix 500 or 5000 based controller?
Regards,
George