User`s manual
7.0 - Troubleshooting Section
Page - 65
7.4 - Motor parameters
1. No movement at all. Check the following:
a. Are both limits held low to AGND and sourcing current out of the pins?
b. Do you have proper supply to A+15V, A-15V, and AGND?
c. Is your proportional gain (Ix30) greater than zero?
d. Can you measure any output at the DAC pin when an O command has been given?
e. Are you tripping your following error limit? Increase the fatal following error limit (Ix11) by setting it to a
more appropriate value, and try to move again.
2. Movement, but sluggish. Check the following:
a. Is proportional gain (Ix30) too low? Try increasing it (as long as stability is kept).
b. Is your "big step limit" (Ix67) too low? Try increasing it to 8,000,000 -- near the maximum -- to eliminate
any effect.
c. Is your output limit (Ix69) too low? Try increasing it to 32,767 (the maximum) to make sure PMAC can
output adequate voltage.
d. Can an integrator help? Try increasing integral gain (Ix33) to 10,000 or more, and the integration limit
(Ix63) to 8,000,000.
3. Runaway condition. Check the following:
a. Do you have feedback? Check that you can read position changes in both directions.
b. Does your feedback polarity match output polarity? Recheck the polarity match as explained above.
4. Brief movement, then stop. Check the following:
a. Are you tripping your following error limit? Increase the fatal following error limit (Ix11) by setting it to a
more appropriate value, and try to move again.
If you are holding position well, but cannot move the motor, you probably do not have your hardware limits held low.
Check which limits I125 is addressed to (usually +/-LIM1), then make sure those points are held low (to AGND), and
sourcing current (unscrew the wire from the terminal block and put your ammeter in series with this circuit if you need to
confirm this). Refer to the section “Installing and Configuring PMAC” for details on checking the limit inputs.
If your motor "dies" after you give it a jog command, you have probably exceeded your fatal following error limit. If this
has happened, it is either because you have asked for a move that is more than the system can physically do (if so, reduce
I122), or because you are very badly tuned (if this is the case, you will need to increase proportional gain I130). To restore
closed-loop control, issue the J/ command.
7.5 - Motion programs
If the program does not run at all, there are several possibilities:
1. Can you list the program? In terminal mode, type LIST PROG 1 (or whichever program), and see if it is there. If
not try to download it to the card again.
2. Did you remember to close the program buffer? Type A just in case the program is running; type CLOSE to close
any open buffer; type B1 (or your program #) to point to the top of the program; and type R to try to run it again.
3. Can each motor in the coordinate system be jogged in both directions? If not, review that motor's setup.
4. Have any motors been assigned to the coordinate system that is not really set up yet? Every motor in the coordinate
system must have its limits held low, even if there is no real motor attached.
Try the following steps for any other motion program problem:
1) Type “&1%100” in the terminal window.
2) Check that you can appropriately Jog only one of the motors that you intend to use in your motion program.
3) Type the following commands in a text editor to be downloaded to PMAC:
close ; Close any buffer opened
delete gather ; Erase unwanted gathered data
undefine all ;
Erase coordinate definitions in all coordinate systems
#1->2000X ; Replace #1 for the motor you want to use and 2000 by the
; appropriate scale factor for the number of counts per user units