Motion Buffers - Omron TJ1-DRT Hardware Reference Manual

System philosophy
2.8

Motion buffers

The motion buffer is a temporary store of the motion instruction
from the BASIC program to the profile generator.
The BASIC program continues while the instruction waits in the
buffer.
There are three types of buffer:
• MTYPE. The current movement that is being executed. mtype
relates to the axis and not to the process.
• NTYPE. The new movement that waits for execution. ntype
relates to the axis and not to the process.
• Process Buffer. The third buffered movement cannot be
monitored. The process buffer relates to the process and not to
the axis.
• It is possible to check if the process buffer is full by checking the
PMOVE process parameter.
When a motion instruction is executed in the BASIC program, the
instruction is loaded into the process buffer and distributed to the
corresponding axis buffer in the next motion sequence.
If a fourth motion instruction is executed and the three buffers are
full, the BASIC program stops execution until a process buffer is
free for use.
HARDWARE REFERENCE MANUAL
fig. 38
BASIC PROGRAM BASIC PROGRAM
CONNECT(1,1) AXIS(2)
....... .......
MOVE(-500) MOVE(-500)
PROCESS BUFFER
....... .......
MOVE(1000) MOVE(1000)
....... .......
CONNECT(1,1) CONNECT(1,1)
.......
fig. 39
Process Buffer
Process 1
Process Buffer
Process 2
Process Buffer
Process 3
Process Buffer
Process 4
Process Buffer
Process 5
Process Buffer
Process 6
Process Buffer
Process 7
Program Buffer
Process 14
Each process has its own
"Process Buffer"
AXIS BUFFER
(one per axis)
Waiting to be executed
NTYPE
MOTION COMMAND
MTYPE
Currently executed
MOTION COMMAND
DEMAND
POSITION
Profile generator
WAITING EXECUTING
Axis 0
NTYPE
MTYPE
Axis 1
NTYPE
MTYPE
Axis 2
NTYPE
MTYPE
Axis 3
NTYPE MTYPE
Axis 15
NTYPE MTYPE
Each Axis has its own
2 buffers: NTYPE & MTYPE
48