Mitsubishi Q2ACPU, User Manual

Page: 76 / 570

6.
6 - 3
DATA COMMUNICATIONS WITH SPECIAL FUNCTION MODULES
6.2 Reading/Writing Data from/to the QnACPU Using Special Direct Devices
As the FROM/TO instruction, the special direct device reads data stored in the buffer
memory of a special function module or writes data to the buffer memory of a special
function module.
The special direct device represents the buffer memory in a special function module as the
QnACPU device.
REMARK
For details on a special direct device, refer to the QnACPU Programming Manual
(Fundamentals).
The special direct device differs from the FROM/TO instruction in that the CPU
module can handle the buffer memory of a special function module as a direct
device.
This can reduce the total number of steps in the program. However, the instruction
processing speed is the same with the FROM/TO instruction.
Example: U10\G10: U10
G10
Indicates the head I/O No.100 of the special function
module. (Hexadecimal)
Indicates the buffer memory address 10. (Decimal)
Example: Writing data to address 0 of the buffer memory in the special function
module loaded at X/Y0, and reading the data of address 1.
(a) Using the FROM/TO instruction (b) Using special direct device