User's Manual

PMAC User Manual
12 Getting Started with PMAC
If not using limit switches (e.g., for a rotary axis, or for a preliminary test set-up), either tie the limits (pins
51 and 53) to analog ground (pin 58), or disable the limit function in software (refer to variable Ix25,
below).
Note:
The direction polarity of the limit pins is the opposite of what many would consider
intuitive. That is, the limit switch at the positive end of travel should be wired into
the -LIM input, and the limit switch at the negative end of travel should be wired
into the +LIM input. If the direction input of the encoder is ever changed, the wiring
of the limit switches must be changed as well. It is important to check and re-check
the direction sense of the limit inputs.
Amplifier Enable Signal (AENAx/DIRn)
Most amplifiers have an enable/disable input that permits complete shutdown of the amplifier regardless of
the voltage of the command signal. PMAC AENA line is meant for this purpose. If not using a direction
and magnitude amplifier or voltage-to-frequency converter, use this pin to enable and disable the amplifier
(wired to the enable line). AENA1/DIR1 is pin 47. This signal is an open-collector output and requires a
pull up resistor to A+15V. For early tests, this amplifier signal may be under manual control. The polarity
of the signal is controlled by jumper(s) E17. The default is low-true (conducting) enable.
Home Flag Signal (HMFLn)
A home switch can be wired between this pin (HMFL1 is pin 55) and analog ground (AGND), or if
powered from the bus, to digital ground (GND). The switch may be normally open or normally closed;
open is high (1), and closed is low (0). The polarity of the edge that causes the home position capture is
programmable with Encoder I-Variables 2 and 3 (I902 and I903 for HMFL1).
Amplifier fault signal (FAULTn)
This input can take a signal from the amplifier so PMAC knows when the amplifier is having problems,
and can shut down action. The polarity is programmable with I-variable Ix25 (I125 for motor #1) and the
return signal is analog ground (AGND). FAULT1 is pin 49. With the default setup, this signal must be
actively pulled low for a fault condition. In this setup, if nothing is wired into this input, PMAC will
consider the motor not to be in a fault condition.
Software Setup for a Motor
PMAC has a large set of Initialization parameters (I-variables) that determine the personality of the card for
a specific application. Many of these are used to configure a motor properly. Once set up, these variables
may be stored in non-volatile EAROM memory (using the SAVE command) so the card is always
configured properly (PMAC loads the EAROM I-variable values into RAM on power-up).
Run the PMAC Executive Program on the PC. The value of an I- variable may be queried simply by typing
in the name of the I- variable. For instance, typing I900 <CR> causes the value of the I900 to be returned.
The value may be changed by typing in the name, an equals sign, and the new value (e.g. I900=3<CR>).
Note:
Remember that if any I-variables are changed during this setup, use the SAVE
command before powering down or resetting the card, or the changes that were
made will be lost.
Alternatively, use the I-variable pages (under the Configuration menu) to view and change these variables
in a more user-friendly fashion.