12
APPLICATION FUNCTIONS
12
- 18
12.1 Transient Transmission Function
12.1.4 SEND/RECV function
(2) RECV function
The RECV function reads data received by the board from the other station using the
mdReceive/mdReceiveEx function.
< RECV function overview >
The board receives data sent from the other station by the SEND instruction/SEND
function, and stores data to the target station channel specified at the sending side.
After the board receives the data, the driver automatically executes the RECV
instruction and stores the received data to the reception buffer of the driver. All data
received and individually stored to channels of the board are stored to the one
reception buffer of the driver which can store up to 128 of data.
Reads data of the specified channel number in the received order from the data
stored in the reception buffer of the driver using mdReceive/mdReceiveEx
function.
< Operation when 128 received data are already stored in the reception buffer of the
driver >
When 128 received data are already stored in the reception buffer of the driver, the
subsequent data are received by the board once, but the driver automatically discards
those received data at the time of storage to the reception buffer of the driver.
When the sending side sent data with "arrival acknowledgment" execution type, the
process of send data is completed normally at the sending side, but data are
discarded.
Board
Driver
User application
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Sending station
Data sent from
other station by
the SEND
instruction
Received data
are stored to the
target station
channel specified
by the sending
station.
RECV
instruction
*1
Received data of Channel 3
Received data of Channel 7
Received data of Channel 1
Received data of Channel 5
Received data of Channel 4
Reception buffer of driver
Received data can
be stored up to 128
disregarding the channel numbers.
Read by the
mdReceive/
mdReceiveEx
function
Received data storage (data)
Send source network No.
Send source station No.
Send source channel No.
Received message
(Actual data)
*1: Executed automatically by the driver.
3
2
1
1
2
3
Board
Driver
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Sending station
Data sent from
other station by
the SEND
instruction
Received data of Channel 3
Received data of Channel 7
Received data of Channel 1
Received data of Channel 5
Received data of Channel 4
Received data of Channel 2
Received data of Channel 6
Reception buffer of driver
Received data can be stored
up to 128 disregarding the
channel numbers.
Discards received data
