Chapter4 FunctionalOverview
©NationalInstruments Corporation 4-5 7344/7334Hardware User Manual
Onboard Programs (7344 only)The 7344 controller has full onboard programmability with the capability
ofex ecuting up to 10 simultaneous motion programs in a real-time
preemptive multitasking environment.
Thisextremely powerful feature is designed for real-time applications that
need tight synchronization and/or minimum latency—from a motion or
other I/O event—andfast command execution.
Youcan execute the entire FlexMotion function set from onboard
programs.In addi tion, the onboard programs support basic math and data
operation functions on up to 120 general-purpose variables.
Implementingpart or all of your motion application as an onboard program
or programs offloadsth e host PC from handling these real-time tasks and
events.This leaves the host PC more availablefor the other integrated tasks,
such asdata acquisition, image processing,user interface, data analysis,
and/oroverall measurement and automation system control.
Onboardprograms can also isolate your application from the non-real-time
operatingsystem of the host PC. Only the bus power is required to correctly
executean onboard FlexMotion program once it is started, and this program
continuesto run even if the host PC hangs, assuming the host power supply
remains.
Youcan run onboard programs from RAM or optionally save them to flash
ROM.The 7344 controller has 64 KB of RAM and 128 KB of ROM
(dividedinto two 64 KB sectors) for program and object storage. You can
runprograms from either RAM or ROM, but you cannot split programs
between the two,a nd you cannot split programs between the two 64 KB
ROMsectors. With an average command size of 10 bytes, a single program
can be as largeas 6,400 commands.A s another example,the 7344
controllercan simultaneously execute10 programs, five from RAM and
fivefrom ROM, with each program up to 1,280 commands long.
Note Refert o the Onboard Programming Functions section of the FlexMotion Software
ReferenceManual, for detailed information on all of these onboard programm ingfeatures.