
B–64113EN–1/01
15. PMC CONTROL FUNCTION
1043
The external workpiece coordinate system shift adjusts the workpiece
coordinate system depending on the shift amount set via the PMC. Each
axis (parameter No. 1220) has this shift amount, and it is added to all the
workpiece coordinate systems for use. The shift amount is not lost by cut
off of the power supply. It is not added incrementally, but each input shift
amount generates a new shift amount. The range that can be input is
0-"7.999 mm or "0.7999 inch.
The machine coordinate system can be shifted by inputting a shift value.
When the shift amount is input, compensation is immediately applied to
the corresponding axis and the machine starts operation. The position
accuracy can be improved by combining this function with sensors.
The specification to shift the axis is the same as that for the external
workpiece coordinate system shift.
The compensation value is specified in signals ED0 to ED15 using a
binary code ranging from 0 to "9.999. This compensation value should
be absolute and the amount the machine actually moves on input is the
difference from the previously stored value. When a large amount of
compensation is applied at one time, an alarm such as “excessive error on
stop” may occur. In this case, input the compensation in several smaller
increments.
(a) External alarm message
The external alarm message holds the CNC in an alarm condition by
sending an alarm number from the external device, as well as a
message that is displayed on the CRT screen of the CNC. Up to four
alarm numbers and messages can be sent at a time; the alarm number
ranges from 0 to 999. The CNC displays adds 1000 to the alarm
number. The message for one alarm number can be up to 32 characters
long. The alarm condition is reset by external data.
(b)External operator message
The external operator message sends the operator message and number
from the external unit to the CNC, with a display on the CRT screen
of the CNC.
Only one message can be transmitted, with a potential message length
of 255 characters. The alarm number ranges from 0 to 999; from 0 to
99, the CNC adds 2000 to the number, while from 100 to 999 the
number is not displayed, only the message is displayed.
However, the number of messages to be displayed with a message
number can be changed by setting parameter No. 6310.
3) External workpiece
coordinate system
shift
4) External machine
coordinate system
shift
5) External alarm
message