Reference Manual

PMAC 2 Software Reference
80 PMAC I-Variable Specifiation
Overtravel Limit Use Bit: With bit 17 equal to zero – the normal case – the +/-LIMn inputs
must be held low to permit commanded motion in the appropriate direction. If there are
not actual (normally closed or normally conducting) limit switches, the inputs must be
hardwired to ground.
Note:
The direction sense of the limit inputs is the opposite of what many
people consider intuitive. That is, the +LIMn input, when taken
high (opened), stops commanded motion in the negative direction;
the -LIMn input, when taken high, stops commanded motion in the
positive direction. It is important to confirm the direction sense of
your limit inputs in actual operation.
If bit 17 (value $20000, or 131072) is set to one (e.g. I125=$2C000), Motor x does not use
these inputs as overtravel limits. This can be done temporarily, as when using a limit as a
homing flag. If the limit function is not used at all, these inputs can be used as general-
purpose inputs by assigning M-variables to them.
Starting in firmware 1.15, bit 17 of Ix25 does not effect the software overtravel limits.
Activation of the software overtravel limits is done by setting the value of Ix13 and or Ix14
to a non-zero value. De-activation is done by setting their values to zero.
MACRO Flag Bit
: If bit 18 of Ix25 is 0, the flag set is wired directly into the PMAC
controller. If bit 18 (value $40000, or 262,144) is 1 (e.g. I125=$4070), PMAC looks for
these flags to come through the MAXCRO ring.
Amplifier Fault Use Bit: If bit 20 of Ix25 is 0, the amplifier-fault input function through
the FAULTn input is enabled. If bit 20 (value $100000, or 1, 048,576) is 1 (e.g.
1125=$10C000), this function is disabled. General-purpose use of this input is then
possible by assigning an M-variable to the input.
Action-on-Fault Bits
: Bits 21 (value $200000, or 2,097,152) and 22 (value $400000, or
4,194,344) of Ix25 control what action is taken on an amplifier fault for the motor, or on
exceeding the fatal following err limit (Ix11) for the motor:
Bit 22 Bit 21 Function
Bit 22=0 Bit 21=0: Kill all PMAC motors
Bit 22=0 Bit 21=1: Kill all motors in same coordinate system
Bit 22=1 Bit 21=0: Kill only this motor
Bit 22=1 Bit 21=1: Kill only this motor
Regardless of the setting of these bits, a program running in the coordinate system of the
offending motor will be halted on an amplifier fault of the exceeding of a fatal following
error limit.
Amplifier-Fault Polarity Bit
: Bit 23 (value 8,388,608) of Ix25 controls the polarity of the
amplifier fault input. A zero in this bit means a low-true input (low means fault); a one
means high-true (high means fault). The input is pulled high internally, so if no line is
attached to the input, and bit 20 of Ix25 is zero (enabling the fault function), bit 23 of Ix25
must be zero to permit operation of the motor.
First Hex Digit
: In the hexadecimal form, bits 20 to 23 combine to form a single
hexadecimal digit.