Specifications

7
■
High speed processing
The requirement for faster processing speed of PLC systems
will never end because faster processing means shorter
production time, more precise control, and better quality
in applications. MSP (Mitsubishi Sequence Processor) per-
formance has been greatly improved compared to the types
used in AnA/AnUCPU. QnACPUs gives roughly 3 times
faster processing speed than AnUCPUs.
■
Large built-in memory and
optional IC card
Each CPU module is equipped with a large built-in memory
in addition to approximately 30k words of internal device
memory. With the largest memory available, the Q4A and
Q4ARCPU can control up to a 124k step program.
■
Global and local devices
MELSEC-QnA offers a new concept in internal device
memory. In support of the multiple programming features
of QnA PLCs, each program module can be installed with
its own internal memory bank, called a ‘local device.’ The
data of the local device does not influence the results of
other program modules, and conversely it is not affected
by other modules either. Local devices, then, can be used
freely within program modules. At the same time, global
devices with a common memory shared by all the program
modules are also available, and can be used for
interlocking of program modules.
■
Macro command
A ladder program block used frequently in a given program
can be registered as a macro command and then utilized
in any other program any number of times with different
input and output devices. Use of this feature eliminates
retyping of the same form of ladder block and helps
standardize programming.
Pre-registered macro command libraries are also available.
The macro library software SW
M
IVD-MSPQ/MSDQ consists
of the following macro commands:
The special function module library MSPQ comprises
ladder program blocks necessary for MELSEC special
function modules such as the RS232C interface module.
The standard ladder program library MSDQ comprises
ladder blocks generally required for machine controls such
as on-delay timers and emergency stop detection.
■
Multiple programs
Up until now, PLC programs were generally composed of
one long program which handled all tasks, but because of
PLC’s scanning operation and program size, programming
and debugging was not easy. Even utilization of a
previously made program for another control application
was not easy to implement.
MELSEC QnA can handle and execute multiple program
modules. At the program design stage, program modules
can be created process by process, function by function
(e.g. of a machine) or designer by designer for concurrent
design. There are many advantages to this approach.
●
Easier to understand because each program module can
be made for specific functions and program modules are
smaller than one long program.
●
Program merging is not necessary after parallel design of
program modules by multiple designers.
●
Easier to make standardized program modules which can
be used repeatedly for other similar projects.
●
Saves time for program up/down loading at debugging
stage because of smaller program size.
■
Q6MEM Series IC memory card
Q6MEM are PCMCIA compatible IC memory cards that can
extend the data memory size of the CPU. There are a
number of memory sizes and types that can be chosen
based on application requirements. Up to 2MB per card is
available in the following formats: SRAM memory only,
SRAM+
EEPROM and Flash ROM+SRAM.
Although an IC memory card is optional, it is required if
the following apply.
●
Sampling trace, Program trace, or Status latch function is
used
●
More than 16 fault records are required
●
Store device comment in CPU
●
File registers are required
●
Local device function is used
●
Program-boot from IC card is required
●
Max. size of program (depending on CPU type) is created
Q4ARCPU
Q3ACPU Q2ACPU (S1)
Q4ACPU
LD X (input) 0.075µs 0.15µs 0.20µs
OUT T (timer) 0.60µs 1.20µs 1.60µs
MOV 0.225µs 0.45µs 0.60µs
+ 0.90µs 1.80µs 2.40µs
Note: Processing time varies depending on accessing device type.
Q3AQ4A
QnA CPU Features
RyansElectric.com