My primary difficulty with servo drives, was separating the jog command that I am used to using as an electrician.
As a typical electrician, when an operator pushes a JOG push button on a typical motor starter circuit, the motor will jog until the pushbutton is released.
In a Kinetix servo environment, when the motor circuit JOG (MOTOR AXIS JOG) command is given, the motor will rotate UNTIL A MOTOR AXIS STOP (MAS) command is given. Jog MEANS KEEP MOVING, even after you release the button... it's jog forever and ever. The servo needs a Motion Axis Stop command to stop moving.
Of course, using PLC logic, you can issue a MAS (Motion Axis Stop) command, by just issuing a command that the Jog pushbutton is no longer actuated, which is what most examples will show.
So, issue a jog command via a pushbutton, but if you take your finger off the pushbutton, it will continue to move UNLESS YOU PROGRAM LOGIC to issue a motion axis stop when the button is no longer active.
A MAM (Motion Axis MOVE) however, will MOVE the motor until it gets to the position that is set in the MAM instruction.
So if you issue a MAM with a given point of travel, the motor will stop at the pre-determined location, such as, move 300 inches and then stop.
This all becomes relevant when you learn how to "override" the commands by using the MOTION DIRECT COMMANDS.
Some things to note:
The Kinetix servo settings are set in the RsLogix Program, if you replace a servo controller, you do not have to re-load the settings via Drive Explore (At my plant at least).
When replacing a controller, you need to be especially carefull when replacing the module. Follow the manual, it will explain how to loosen a few screws and tip the module up at a 45 degree angle to remove, and set back in at a roughly 45 degree angle back in to re-seat. Be careful with that. Pulling the bad controller out isn't too difficult, but when installing the replacement, be careful, you can bend the pins. Try to get everything aligned as best you can, but realize the pins only re-seat after you use a screwdriver to "pull-in" the connection" with the screws. If it doesn't seem to be seated properly, it's not seated properly. UNDO-REDO.
When working on a backplane with several controllers, if you REMOVE an uneeded one as a replacement, you need to install a JUMPER block in the empty slot, SOLD by, you guessed it ALLEN BRADLY. I seem to remember having some problems with a servo module, without any spares, but we were not using another one in the chassis. We used that one as a replacement, but had a difficult time, because even inhibiting the module (the one we had pulled to use as a replacement) caused a fault without that jumper card.
Also, had an issue where the shielding/grounding clamp was not tied to the motor cable. This caused another servo within the rack to lose positioning. TIE the MOTOR SHIELDS TO GROUND. There is a nice shielding clamp that comes with these, but it's hit or miss on whether or not it's a screwdriver, or hex. Also the extended clamp requires about a 7 inch screwdriver or hex key to remove, so get one of those.
Overall, your best bet, is to set up a test bench, using an actual LOGIX Processor. You can't simulate motion instructions using RSEMULATE. Set up a real controller and TREND the code to get an idea of what the commands do.
