Toshiba AS311 - Manual (Page 41)

User’s Manual
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5. Operation Procedure
5.2 Received message read sequence
5.2.1 Flag 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 Receiving error
AS311 sets the message into buffer AS311 sets the error information into
memory (receiving data area), and buffer memory (parameter area)
sets the received message length into
buffer memory (parameter area)
AS311 sets Read ready to ON, and AS311 sets Receive error to ON, and
resets Receive complete to OFF resets Receive complete to OFF
T3 reads the message form buffer T3 reads the error information from
memory (receiving data area) buffer memory (parameter area)
by READ instruction by READ instruction
T3 resets Read start to OFF T3 resets Read start to OFF
AS311 resets Read ready to OFF AS311 resets Receive error to OFF