Data Communications Using Cpu Shared Memory - Mitsubishi MELSEC-Q Series User Manual

14
COMMUNICATIONS BETWEEN CPU MODULES

14.3 Data Communications Using CPU Shared Memory

(1) Data communications using CPU shared memory
Data communication form
Between programmable controller CPU and C
Controller module
Between Motion CPU and C Controller module
Between C Controller modules
(2) CPU shared memory structure
(3) Functions
QBF_ToBuf
QBF_FromBuf
This function enables data communications between the C Controller module and
CPU module using the CPU shared memory.
Use the bus interface functions to create the user program of the C Controller module.
The following describes the data communication methods using the CPU shared
memory and its selection.
(a) Data communication method using CPU shared memory
There are the following two methods for data communications using CPU shared
memory.
• Data communications using the auto refresh of the programmable controller
CPU or Motion CPU
• Data communications without using the auto refresh of the programmable
controller CPU
(b) Selection of data communication method
When making data communications using the CPU shared memory, select the
method according to the target CPU module type.
The following indicates whether data communications are available or not in each
data communication form.
Table14.8 Applicability of data communications
Auto refresh used
Refer to Section 14.3.1 for the CPU shared memory structure of the C Controller
module.
The following indicates the functions used for data communications using CPU
shared memory.
Table14.9 Functions used for data communications using CPU shared memory
Function name
Writes data to the CPU shared memory at the specified module
*1
position and the buffer memory of the intelligent function module.
Reads data from the CPU shared memory at the specified module
*2
position and the buffer memory of the intelligent function module.
* 1 The mdSend function can be used instead of the QBF_ToBuf function.
* 2 The mdReceive function can be used instead of the QBF_FromBuf function.
14.3 Data Communications Using CPU Shared Memory
Data communication method
Auto refresh not used
Function
Reference section
14.3.2,
14.3.3 (1)(a)
14.3.2
14.3.3 (1)(b)
Applicable, : Not applicable
14
- 8
9
10
11
12
13
14
15
16