Mitsubishi QD51-R24 User Manual

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MELSEC-Q
3 SPECIFICATIONS
3.12 Running a BASIC Program by Multitask Processing
Here, the method of running a QD51 (-R24) BASIC program, etc. is explained.
3.12.1 Multitask processing
The QD51 (-R24) us a unit which operates by BASIC programs created by the user.
The QD51 (-R24) has one main CPU (central processing unit).
Multitasking accomplishes parallel operations by successively switching the execution
between multiple BASIC programs (up to 2 tasks).
1) 2)
3)
4)
5) 6)
Shows the order of
main CPU processing.
[Processing in the case of two tasks]
Example
Task 1 Task 2
In QD51 (-R24) multitask processing, switching of BASIC program execution is done
when the conditions shown below occur.
• When "Task schedule time (50 ms)" has passed.
• When a data input/output (data send/receive) command is run with respect to a
screen, keyboard, disk, peripheral device or external device.
• When a command is run which carries out control of (interrupts, stops, ends) BASIC
program execution.
• When a command is run which carries out multitask control (synchronizes execution,
starts or changes the priority, etc.).
• When a program execution interrupt state is canceled (input/output is completed, the
specified time has passed, etc.)
REMARK
Refer to the Programming Manual (Commands) concerning details of multitask
processing and commands which switch the execution of programs.

Mitsubishi QD51-R24 Specifications

General

Model	QD51-R24
Type	High-speed counter module
Number of channels	2
Isolation	Photocoupler isolation
Operating temperature	0 to 55 °C
Storage temperature	-25 to 75 °C
Manufacturer	Mitsubishi
Counting range	-2147483648 to +2147483647
Power supply	5 VDC (from main module)
Current consumption	0.3 A
Communication method	RS-232, RS-422/485
Data length	7 or 8 bits
Stop bit	1 or 2 bits
Parity	None, Even, Odd
Maximum input frequency	500 kHz (Differential line driver), 200 kHz (Open collector)
Flow control	None, XON/XOFF, RTS/CTS