Mitsubishi MELSEC LJ71C24, User Manual

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12 DEDICATED INSTRUCTIONS
12 DEDICATED INSTRUCTIONS
Dedicated instructions are used to simplify programming when using intelligent function
module functions.
This chapter describes the LCPU dedicated instructions used for the C24.
12.1 Dedicated Instruction List and Available Devices
(1) Dedicated instruction list
The following table lists the dedicated instructions explained in this chapter.
Application
Dedicated
instruction
Description of function Reference
On-demand function
transmission
ONDEMAND 1
Sends data using the on-demand function of the MC
protocol.
Section 12.2
Predefined protocol
communication
CPRTCL
Executes the protocol setting data written to the flash ROM
using the predefined protocol support function of GX
Works2.
Section 12.3
OUTPUT 1
Sends data for the specified data count. Section 12.4
Nonprocedural protocol
communication
INPUT 1
Reads received data. Section 12.5
BIDOUT
1
Sends data for the designated data count. Section 12.6
Bidirectional protocol
communication
BIDIN
1
Reads received data. Section 12.7
Communication status
confirmation
SPBUSY
Reads the status of data transmission/reception via a
dedicated instruction.
Section 12.8
Receive data clear CSET
Perform the receive data clear without stopping the
transmission processing during the nonprocedural protocol.
Section 12.9
POINT
Do not change data values (control data, request data, etc.) designated by a
dedicated instruction until the execution of the dedicated instruction is completed.
1 To change the following values preset in the buffer memory for use of
dedicated instructions, use GX Works2 or execute the CSET instruction
(Initial setting) before starting data exchange. (Refer to User's Manual
(Application).)
• Word/byte units designation (address: 96
H
/136
H
)
• Buffer memory head address designation for on-demand function
designation (address: A0
H
/140
H
)
• Transmission buffer memory head address designation (address: A2
H
/
142
H
)
• Transmission buffer memory length designation (address: A3
H
/143
H
)
• Receive buffer memory head address designation (address: A6
H
/146
H
)
• Receive buffer memory length designation (address: A7
H
/147
H
)
The dedicated instructions are executed based on the values preset in the
buffer memory at module startup or those that have been changed by the
CSET instruction (Initial setting).
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