Processing When Simultaneous Transmission Is Performed During Full-Duplex Communications; Processing When Simultaneous Transmissions Occur - Mitsubishi Electric MELSEC iQ-R Series User Manual

4.3
Processing when Simultaneous Transmission is
Performed during Full-Duplex Communications
This section explains the processing when simultaneous transmission is performed during full-duplex communications.

Processing when simultaneous transmissions occur

The following explains the processing by C24 when the target device and C24 transmit data at the same time during data
communications using the bidirectional protocol.
Note that transmission from a target device and from C24 are not performed simultaneously for data communication by half-
duplex communications. (Page 243 DATA COMMUNICATIONS USING HALF-DUPLEX COMMUNICATIONS)
The processing on the C24 side differs depending on the settings with Engineering tool when transmission from a target
device and C24 is performed at the same time.
Set "Send data enable/disable" and "Receive data enable/disable" to "Enable" or 'Disable" with Engineering tool.
Navigation window  [Parameter]  [Module Information]  "Module Name"  [Module Parameter]  "Basic Settings"
 "Various control specification"
The setting value for "Send data enable/disable" and "Receive data enable/disable" is stored in the following area on the
buffer memory.
For processing of transmitted/received data on the C24 side for each setting of the 'simultaneous transmitted data valid/invalid
designation' (Un\G155/315), refer to the "Processing of transmitted/received data when simultaneous transmission occur".
Setting contents with
Engineering tool
Send data enable/disable:
Enable
Receive data enable/disable:
Enable
Send data enable/disable:
Disable
Receive data enable/disable:
Enable
Send data enable/disable:
Enable
Receive data enable/disable:
Disable
Send data enable/disable:
Disable
Receive data enable/disable:
Disable
(●-m) is the number showing the correspondence with the messages in the figures below.
Page 105 Processing of transmitted/received data when simultaneous transmissions occur
4 DATA COMMUNICATION USING BIDIRECTIONAL PROTOCOL
104

4.3 Processing when Simultaneous Transmission is Performed during Full-Duplex Communications

Value stored to buffer
memory
(Un\G155/315)
0000H
0100H
0001H
0101H
C24 processing contents
Processing related to message
transmission
Waits to receive the response message(-
2) while checking time-out after data
transmission (-1) is complete.
Notifies normal completion or abnormal
completion according to whether or not the
response message is received to the CPU
module via the buffer memory.
Notifies a simultaneous transmission error to
the CPU module via the buffer memory after
data transmission(-1).
Does not wait for a response massage (-2)
in reply to data transmission (-1).
Waits to receive the response message (-
2) while checking time-out after data
transmission (-1) is complete.
Notifies normal completion or abnormal
completion according to whether or not the
response message is received to the CPU
module via the buffer memory.
Notifies a simultaneous transmission error to
the CPU module via the buffer memory after
data transmission(-1).
Does not wait for a response massage (-2)
in reply to data transmission (-1).
Processing related to massage
reception
Transmits a response message (-2) after
data reception (-1) is complete.
Notifies the received data and reception
result to the CPU module via the buffer
memory.
Transmits a response message (-2) after
data reception (-1) is completed.
Notifies the received data and reception
result to the CPU module via the buffer
memory.
Ignores data reception (-1) and discards
the received data. Does not transmit a
response message (-2).
Does not inform the CPU module that data
was received.
Ignores data reception (-1) and discards
the received data. Does not transmit a
response message (-2).
Does not inform the CPU module that data
was received.