Reference Manual

PMAC 2 Software Reference
218 PMAC On-Line Command Specification
Therefore, an entry in the torque compensation table is numerically 256 times bigger than the
corresponding servo-loop torque output.
The first entry is the correction at one spacing from the motor zero position (as determined by
the most recent home search move or power-up/reset), the second entry is the correction two
spacings away, and so on. PMAC computes corrections for positions between the table
entries by a first-order interpolation between adjacent entries. The correction from the table
at motor zero position is zero by definition.
The correction is the magnitude added to PMAC’s servo loop output at that position. If
PMAC’s command is positive, a positive value from the table will increase the magnitude of
the output; a negative value will decrease the magnitude of the output. If PMAC’s command
is negative, a positive value from the table will decrease the magnitude of the output in the
negative direction; a negative value will increase the magnitude of the output.
The last entry in the table represents the correction at {count length} distance from the
motor’s zero position. Since the table has the capability to roll over, this entry also represents
the correction at the motor’s zero position. For this reason, the last entry should virtually
always be set to zero.
Note:
PMAC will reject this command, reporting an ERR003 if I6=1 or 3, if
any TCOMP buffer exists for a lower numbered motor, or if any
BLCOMP, TBUF, ROTARY, or GATHER buffer exists. Any of
these buffers must be deleted first. TCOMP buffers must be defined
from high-numbered motor to low-numbered motor, and deleted from
low-numbered motor to high-numbered motor.
I51 must be set to 1 to enable the table.
See Also
Torque Compensation (Setting Up a Motor)
I-variables I51
On-line command DELETE TCOMP
DEFINE UBUFFER
Function
Create a buffer for user variable use.
Scope
Global
Syntax
DEFINE UBUFFER {constant}
DEF UBUF {constant}
where:
• {constant} is a positive integer representing the number of 48-bit words of PMAC
memory to reserve for this purpose
Remarks
This command reserves space in PMAC’s memory for the user’s discretionary use. This
memory space will be untouched by any PMAC automatic functions. User access to this
buffer is through M-variables, or possibly through on-line W (write) and R (read) commands.
The buffer starts at PMAC memory address $9FFF and continues back toward the beginning
of memory ($0000) for the number of long (48-bit) words specified by {constant}. This
memory space can be subdivided any way the user sees fit. On PMACs with battery backup,
the values in the buffer at power-down will still be there at power-up. On PMACs with flash
backup, the values in the buffer at the last SAVE command will be copied from the flash
memory into the buffer at power-up or reset.