Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1682

• After the protocol whose communication type is "Send and receive" is canceled, clear the receive data.
When data is received after cancellation, the receive data is held in the OS area (receive data area). This
occurs when a response from the external device is slow. For how to clear receive data, refer to Page 1702
Clearing Receive Data.
• While the value set to "Protocol cancellation specification" is 1 (Cancellation requested), another
G(P).CPRTCL instruction cannot be executed.
■Special protocol
The following functions are available by executing special protocols with the G(P).CPRTCL instruction.
Functions
Clearing receive data
Send/receive data monitoring start/stop
RS/DTR signal status specification
In control data (s)+2 to (s)+9 of the G(P).CPRTCL instruction, specify the number of the special protocol of the function to be
executed.
Functions
Clearing receive data
Send/receive data
monitoring start/stop
RS/DTR signal status
specification
*1 When a special protocol is executed, the keyword is defined as the character string that is stored in the protocol name of the protocol
execution history.
Precautions
• The following table summarizes the processes that take place if another instruction is issued while the G(P).CPRTCL
instruction is active or the G(P).CPRTCL instruction is issued while another instruction is active with the same channel.
Instruction to execute
*2
concurrently
G(P).CPRTCL
G(P).PUTE
G(P).GETE
G(P).SPBUSY
ZP.UINI
*2 The following instructions are not available with the same channel as for the G(P).CPRTCL instruction because they use a
communication protocol different from the one used by this instruction. In addition, if these are used with the same channel as for the
G(P).CPRTCL instruction, a communication protocol setting error (7FF2H) will occur (except for the Z.BUFRCVS instruction).
• G(P).ONDEMAND, G(P).OUTPUT, G.INPUT, G(P).BIDOUT, G(P).BIDIN, Z.BUFRCVS, G(P).PRR, and ZP.CSET instructions
• The local device and the file register for each program are not available for setting data.
20 SERIAL COMMUNICATION INSTRUCTIONS
1680
20.2 Executing the Protocols Registered for the Predefined Protocol Support Function
Description
Enables the receive data to be cleared from the OS area.
Specifies the start or stop of send/receive data monitoring.
When special protocols 202 or 203 is executed, the module sets the monitor start instruction "0001H" or the
monitor stop instruction "0000H" for the send/receive data monitoring specification (address: 2018H, 2118H).
Specifies the on/off state of the RS(RTS) and ER(DTR) signals.
When one of special protocols 204 to 207 is executed, the module turns on/off the bit corresponding to the RS/
DTR signal status specification (address: 92H/132H).
For details on the RS/DTR signal status specification, refer to the following.
 MELSEC iQ-R Serial Communication Module User's Manual (Application)
Special protocol Type
number
201 Clearing receive data
202 Start send/receive data monitoring
203 Stop send/receive data monitoring
204 Turn on the ER (DTR) signal
205 Turn off the ER (DTR) signal
206 Turn on the RS (RTS) signal
207 Turn off the RS (RTS) signal
Possibility of
concurrent execution



Handling for concurrent execution
The instruction is ignored and does not start processing until the active instruction
completes.
Concurrent execution is, however, possible if they use different channels.

A dedicated instruction concurrent execution error (7FF0H) occurs in the second
instruction.
*1
Keyword
Receive Data Clear
Send/Recv Monitor Start
Send/Recv Monitor Stop
DTR ON
DTR OFF
RS ON
RS OFF