5. Operation Procedure
5.2 Received message read sequence
5.2.1Flag control timing
In case of receiving a message, the following flags are used for handshaking between T3 and AS311. These flags are the bits of the I/O registers assigned to the AS311. Refer to section 4.1.
Read ready | Bit 7 of XW(n) for channel 1 or XW(n+1) for channel 2 |
Receive complete | Bit 6 of XW(n) for channel 1 or XW(n+1) for channel 2 |
Receive error | Bit 5 of XW(n) for channel 1 or XW(n+1) for channel 2 |
Read start | Bit 7 of YW(n+2) for channel 1 or YW(n+3) for channel 2 |
The message receiving procedure is as follows. It is called “received message read sequence”.
AS311 receives a message
AS311 sets Receive complete to ON
T3 sets Read start to ON
Normal receiving
AS311 sets the message into buffer memory (receiving data area), and sets the received message length into buffer memory (parameter area)
AS311 sets Read ready to ON, and resets Receive complete to OFF
T3 reads the message form buffer
memory (receiving data area)
by READ instruction
T3 resets Read start to OFF
AS311 resets Read ready to OFF
Receiving error
AS311 sets the error information into
buffer memory (parameter area)
AS311 sets Receive error to ON, and
resets Receive complete to OFF
T3 reads the error information from buffer memory (parameter area) by READ instruction
T3 resets Read start to OFF
AS311 resets Receive error to OFF
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