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Eagle Signal MTA330A6 05 What kind of "PLC" or control is this?

4 posts in this topic

Hello Friends

I need to replace this control with a PLC, I have not found info about this device. The only that I know that is a stepswitch.

This device is connected to some valves, sensors, and electronic timers.

Do you know How it works?

Any information would be appreciated.

Thanks in advance.

MTA330A6_05.jpg

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Posted (edited)

I tried to find some info but could not locate manuals.  If you have a model number, it would be helpful.  I believe these devices are timers with multiple outputs.  In the case of this one, it looks like it has 30 possible outputs and your system has 25 of those outputs wired.  As the drum turns, the outputs turn on as the "flags" placed on the drum reach the actuation point (one spot along the drum where the individual switches are placed).  This looks like an industrial version of a vacation timer for lights in a home to make it look like people are in the house.  To convert this to a PLC, you will need to have or develop a wiring schematic that identifies which switches on the device control what devices on your equipment.  Once you have that, you should be able to draw another diagram that identifies the relationship of each switch flag to each other, which will be time-based.  If the unit still works and my assumptions are correct, it would be helpful to know how long it takes the drum to rotate one complete revolution.  If you know that, you could determine the duration of each of the switches "on" time based on the number of degrees the "flags" cover.  From there you could code your PLC based on the relationships you find with your diagrams.  I would be really interested in seeing a schematic for your system if you have one.  Good luck.  That is definitely an interesting piece of early automation.  A "keeper" for a collector, for sure!  Good luck in your conversion.  Please update this post with your findings.  

After re-reading this, I see you had the model number there the whole time, in plain sight!  Sorry about that.

Edited by drforsythe
missed important info

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Posted (edited)

I think this is rather a sequencer than a PLC. I think it activates outputs in sequence which is different than the PLC basic principles. You may replace this device and even some of those connected outside to it (timers for example) with an ordinary PLC. To do that first thing is to find out how does it work. I was unable to find any user manual. I don't know if it's in working condition or not. If operable you could measure the output signals and draw a time chart. 
 

 

Edited by IvanBratanov

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it is an ancient electromechanical form of control called drum sequencer. basically it is a multi-pole selector switch that is turned slowly by a geared motor. predecessors of this ware mechanical... they were powered by by spring or gravity and would be used in music boxes or automatons. basically instead of being powered by mechanical crank or spring or weight, it is powered by a motor. and drum is activating switches instead of mechanical levers.

https://www.youtube.com/watch?v=vzB5J0jIU6s&ab_channel=EricC.

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