Applicable Dedicated Instructions; Applicable Connections; Communication Structure - Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual

Applicable dedicated instructions

The following table lists the dedicated instructions used for communications using the fixed buffer.
For details on dedicated instructions, refer to the following.
 MELSEC iQ-R Programming Manual (Module Dedicated Instructions)
List of dedicated instructions
The following table lists the dedicated instructions used by each module.
Instruction Description
*1
GP.CONOPEN Establishes a connection.
OPEN
*1
GP.CONCLOSE Closes the connection.
CLOSE
BUFRCV Reads the receive data from the external device.
BUFRCVS Reads the receive data with an interrupt program.
BUFSND Sends data to the external device.
*1 This function cannot be used when "Q Compatible Ethernet" is selected in the network type.

Applicable connections

The connections No.1 to 16 of the P1 connector can be used for the communications using the fixed buffer.
Communications using the fixed buffer cannot be used with the P2 connector.

Communication structure

This section describes the mechanism of communication with fixed buffer communication.
Data flow
Dedicated instructions are used to send and receive data in fixed buffer communication ( Page 69 Applicable dedicated
instructions)
With "Procedure Exist", the CPU module and external device exchange data one-on-one. A handshake is established with the
external device when sending data form the CPU module and receiving data from the external device.
With "No Procedure", data is sent from the CPU module and received from the external device without a procedure.
BUFSND instruction
BUFRCV instruction
CPU module
RJ71EN71
Fixed buffer
No.1
No.2
No.3
No.4
External device
No.16
1 FUNCTIONS
1.5 Communications Using the Fixed Buffer
1
69