Gemini GV6K and Gemini GT6K Programmer's Guide

Introduction to Multi-Tasking
What is Multi-Tasking Multi-tasking is the ability of the Gem6K to run more than one
program at the same time. This allows users to manage independent activities, aside from just
motion.
Why use Multi-Tasking
• Multiple independent tasks can act on the same process or same axis.
• A supervisory program can control and coordinate multiple processes.
What is a Task A system task is a program execution environment, not a program. Each
task runs independently. Each task can be used to run independent programs. Any task may
run any program. Multiple tasks could even be running the same program simultaneously.
Each task may either be:
• Running a program
• Monitoring ON, ERROR, or INSELP conditions
• Inactive (not running a program or monitoring conditions)
Using Multi-Tasking to Run Programs
Use the Wizard
Motion Planner provides
a Multi-Tasking wizard,
accessed from the
Editor. The wizard leads
you, step by step,
through the process of
setting up for multitasking.
Multi-tasking is initiated by the Task Supervisor. The supervisor is the Gem6K’s main
program execution environment — it runs the STARTP program and contains the command
buffer and parser. If the multi-tasking feature is not being used, the supervisor is the lone
program execution environment of the Gem6K, as shown in Figure 1. When multi-tasking is in
operation, the supervisor is referred to as “Task 0”.
Resources
I/O
Inputs
Outputs
Limits
Triggers
Serial Ports
PORT1 (RS-232)
PORT2 (RS-232/485)
Ethernet
Axis
GEM6K
Supervisor
Run Start-up Program
Execute Programs
Monitor Conditions
Command Buffer & Parser
Program Memory
move1
math
inout
fill
move2
seal
gohome
move3
main
Variables
VAR
VARB
VARI
VARS
Figure 1: Gem6K Supervisor, with no Multi-Tasking
The Gem6K can have a maximum of 10 tasks, in addition to the Task Supervisor (Task 0).
Each task acts as an individual program execution environment. The boxes shown under
Resources in Fig. 1, and the following Figures, represent the resources that the supervisor and
tasks monitor and manipulate (see list below). These resources can be shared with other tasks.
• I/O..................................Inputs and Outputs (onboard I/O and expansion I/O bricks)
• Communication ports ....“RS-232”, “RS-232/485”, and “ETHERNET”
202 Gem6K Series Programmer’s Guide