Direct Soft Drum Function

I am working with a Direct Soft PLC and I need to better understand what a Drum function is. Does anyone know what this means?

I appreciate it

From the DL06 Manual:

"The Event Drum (EDRUM) instruction in the DL06 CPU electronically simulates an electro-mechanical drum sequencer."

DL06 Micro PLC User Manual, 3rd Edition Rev A. Section 6. Page 6-2.

Mark

The DRUM function is the easiest. It's a pure time-per-step function. Read the section on DRUM Instruction Programming in your CPU manual at least through the DRUM instruction. Write one and start playing. You don't even need to hook up any real-world output devices, just watch the lights.

As an assignment, make a complete stop light control (ducking bricks from other members) with just one instruction. It can be done. I did it as an exercise to learn the basics of this instructuion. The other forms of this instruction add further controls in step and output control.

re: Drum instructions

From what I read in the help manual, Drum sequencers can operate on a time or event situation. I tryed but failed because I wanted it to work like an event sequence not time. I had 4 tower fans that were controlled by a multi-output controller and because of the way it was wired, The fans never rotated usage. I created a input in the plc to go high when the next fan was called on. This was the trigger. I could not add 1+1=x to rotate the sequence. I am learning. So I tryed to use a drum sequencer to trigger events. Not time. I Tryed and tryed and gave up. This was long before I discovered this fourm. I ended up writing miles and miles of code to make up for this shortfall. And the program works but I still want to understand why I could not make the drum sequencer work.

maintenanceman38 said:

From what I read in the help manual, Drum sequencers can operate on a time or event situation. I tryed but failed because I wanted it to work like an event sequence not time. I had 4 tower fans that were controlled by a multi-output controller and because of the way it was wired, The fans never rotated usage. I created a input in the plc to go high when the next fan was called on. This was the trigger. I could not add 1+1=x to rotate the sequence. I am learning. So I tryed to use a drum sequencer to trigger events. Not time. I Tryed and tryed and gave up. This was long before I discovered this fourm. I ended up writing miles and miles of code to make up for this shortfall. And the program works but I still want to understand why I could not make the drum sequencer work.

Click to expand...

When you say trigger, what was it doing? Was it the input to operate the drum, or an event that moved to the next step of the drum?

I had a few learning experiences setting up my first EDRUM, but now that I have a feel for it, I will be using these a lot more in the future. They are very handy tools.

I am sorry for the long delay, It has been hectic at my work the past 2 weeks but I still want to understand this. The trigger is to make the drum sequence to the next event. But I could never make it work. What did you mean by an input to operate the drum? I think I saw this and held it high. but I may be wrong as I do not remember. That was 4 months ago.

Do you know what a player piano is? If so just look at the drum on it. How about a music box, turn the crank that turns the drum. They need some thing to start them to make them work and keep going.

If this is to old for you the present we call it PLC scan. They all are looking for the little bump in the drum we call inputs to give us a output.

A drum simulates the timer in your washing machine or dishwasher. A DRUM is a straight timer. Timer motor is usually always running, and stopping the motor is the only way to control it.
On a washing machine, the timer motor can pause during fill. The motor will be off until the tub is full. The switching of the Fill Switch is called an EVENT. If you need this feature, then use an EventDRUM, EDRUM.
It works on both time and events. When the event is true, it turns the timer motor on and starts timing.
Events and time are on the left side of the box. Outputs are on the top of the box.
The dots represent the cam lobes on a timer (I can't think of a good way to word this part. Someone help me out here).

The Washing Machine Operator can pull out the timer knob to stop it, or rotate it to the end to reset it. These control functions are more are done by the inputs on the left.

Look at your washing machine, and think about how you would do that with a PLC. Then, read about DRUM or EDRUM in chapter 6 of the Automation Direct DL06 manual.