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ifriarod

1756-M02AE, Master - Slave

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Hi to all of you, guys. I have one servocard 1756-M02AE, i have connected two Baldor-FlexDrives to the card; the servomotors are conecte to the same shaft, there are in both shaft ends; what do i need to do a master-slave config?. I have used a 3 axis configuration before, to do a gantry sys; but not a master-slave configuración. Thanks for any advice. Isaias Frias Rodriguez

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I wouldn't use a master slave configuration unless I had to. I would issue the same MAM command to the two axes at the same time.

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Create a virtual axis and gear the real axes to it. Do all moves on the virtual axes.

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Could you elaborate on why you do this? Just curious

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Since the two axes are mechanically tied together, it is imperative that they are in sync. With the asynchronous nature of the CLX, I believe that if you issue separate move commands,even from the same ladder rung, there can be a delay between the start on each axis. i.e. one axis starts to accelerate while the other is still holding position. By gearing both to a virtual axis, the actual output to the servos is coordinated in the MO2 and the real axes are synchronised. Now, I know Peter has intimate knowledge of the internal workings of the MO2 modules, so if I'm incorrect on any points I'm sure he will put me straight.

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Very good point. I had never thought of it that way Thanks

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Gerry, this is a good question. Will two MAM command issued an the same rung ALWAYS send the same positions to the M02AE axes at the same time? The axes just go to the next point provided. The motion axes don't know anyting about being geared or not. This is a question for the engineers that write the code on the PLC side. I will ask one of our engineers who may know more because he is in charge of the Rockwell projects and talks to their engineers. I haven't talked to a Rockwell engineer in years now. I know on our controller that commands issued at the same time will be executed at the same time so the easy way is to issure the same command to multiple axes. We make this easy to do. We make a BIG deal output being synchronous and deterministic.

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The answer to two MAMs, is, no work in sinc; there is always a delay between them; and always get a servodrive fault; the doubt of Peter Nachtway is cleared (i think). The situation is; my client have a mesh welding machine; the sys is feeded by a shaft with 2 servomotors atached to it. The machine have two servodrive indramat (both is using just one output from m02ae), now is changing the servomotors and drives to one servodrive and motors mark (baldor). There is my question, if it is possible to do a master/slave control with CLX, or continue using the last electrical conecction. Thanks, for your help. Isaias Frias

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Wait, are you saying both servo drives are controlled by the same -10 to +10 VDC output from the M02AE? One is not hooked to axis 1 and the other to axis 2?

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I'm with TWControls - What is your setup? Two servos mechanically coupled together ? Two servos independently controlling two axis where one axis must follow the other? If Mechanically Coupled then MO2AE setup is "One axis of 1756M02AE would control two drives but receive feedback from one motor only" - In a better system the servo drives are both connected and use a droop function that permits them to load share across the mechanically coupled axis. Edited by michael G

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Yes, the last config was as TWControls & Michael G says. It worked, but now i want to know how to do that (master/slave), if it is possible of course. I f not, then will use the last config. Thanks Guys Isaias Frias

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Hi guys. I think the answer is MAG; i will do my tests. Thanks again Isaias Frias

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Hi guys This my opinion: Before you create the master virtual axle, and after lockup your two axis whit gearing instruction “MAG” . Master command Reference to Virtual Axle From Virtual Axle to Real Master (Axle1). From Virtual Axle to Slave (Axle2) Virtual Master =? Axle 1 MAG(Slave1,Master,Gear_Ctrl,0,1.0,1,1,Command,Real,Disabled,100,% of Maximum) Virtual Master =? Axle 2 MAG(Slave2,Master,Gear_Ctrl,0,1.0,1,1,Command,Real,Disabled,100,% of Maximum) For Axle 1 put on Properties-Axis / Limit set “Position Error Tolerance” to correct value detect from auto-tune For Axle 2 put on Properties-Axis / Limit set “Position Error Tolerance” to high value (Limit Axis1 multiply for 5 ) In this way the Axis 2 (Slave) isn’t possible to go “Error-Position” . After you check the actual Error-Position of Axle2, and compare this error to Trigger-Tolerance position. When the absolute error-position is over the your Trigger-Tolerance position, you must actualized correction whit Motion Axis Move instruction “MAM” over the Gearing instruction MAG+MAM In this way you can possible Repartition Torque reference to slave Axle.

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