Communications
State Transition Diagram
RS232C Communications
Transmitting Module EOT is received.
| Size Number of command |
| |
| bytes + 3 | One character is received. | |
| T2 stop |
| |
| Size Number of command | ||
Waiting for EOT |
|
| |
|
| bytes - 1 | |
|
| ||
|
|
|
|
|
|
|
|
There are requests for transmission (within the number of retries).
ENQ transmission and T2 start.
ENQ is received and in slave mode.
ENQ is returned to receiving buffer 
(To reception processing)
There are requests for transmission but the number of retries is exceeded.
The number of retries is to be reset once. A request for transmission is cleared.
Transmission of block
|
|
|
|
|
T2 timeout |
| Size becomes zero. | ||
|
| |||
The number of retries |
|
|
|
|
| T2 START | |||
is counted once. |
| |||
|
|
|
| |
T2 stop |
|
|
|
|
Transmission buffer is |
|
|
|
|
cleared. |
|
|
|
|
|
|
|
| |
| Waiting for ACK/NAK |
| ||
|
|
|
|
|
NAK is received or T2 |
| ACK is received. |
times out. |
|
|
| The number of retries | |
|
| |
| ||
The number of retries is |
| is reset. |
counted once. |
| T2 stop |
T2 STOP |
| The request for |
Transmission buffer is |
| transmission is cleared. |
cleared. |
|
|
Idling
ENQ
EOT is transmitted. T2 start
| T2 timeout |
| T1 times out or checksum |
|
| Reception is successful | |||||
|
|
|
| error occurs when size |
|
| (checksum is OK when size | ||||
| NAK is transmitted. |
| |||||||||
|
| becomes 0. |
|
| becomes 0). | ||||||
| T2 stop |
|
|
|
|
|
|
|
|
| |
|
| NAK is transmitted. |
|
|
|
| |||||
|
|
|
|
|
| ACK is transmitted. | |||||
|
|
|
| T1 stop |
|
| T1 stop | ||||
|
|
|
|
|
|
|
|
|
|
|
|
Waiting for the number | Receiving | |
of command bytes | Remaining blocks | |
The number of command bytes is | One character is received. | |
received. | ||
|
Size | Number of command bytes +3 | Size | Number of command bytes | |
Sum | Sum + received characters | |||
Sum | Number of command bytes | |||
T1 start |
| |||
|
|
|
T1 start, T2 stop
Receiving module
164