YASKAWA VIPA System 200V, Руководство пользователя

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Manual VIPA System 200V Chapter 4 Serial communication
HB97E - CPU - RE_21x-2BS03 - Rev. 15/16 4-7
The following time-outs apply :
Acknowledgement delay time: (QVZ) = 2000 ms
Character delay time: (ZVZ) = 220 ms
The QVZ is monitored between STX and DLE and between BCC and DLE.
ZVZ is monitored for the entire period of receiving the message.
When the QVZ expires after an STX, the STX is repeated. This process is
repeated 3
*)
times after which the attempt to establish a connection is
terminated by the transmission of a NAK. The same sequence is completed
when a NAK or any other character follows an STX.
When the QVZ expires after a message (following the BCC-byte) or when a
character other than DLE is received the attempt to establish the
connection and the message are repeated. This process is also repeated
3
*)
times after which a NAK is transmitted and the attempt is terminated.
*) adjustable via parameter
When the procedure driver is expecting a connection request and it
receives a character that is not equal to STX it will transmit a NAK. The
driver does not respond with an answer to the reception of a NAK.
When ZVZ expires during the reception, the driver will send a NAK and wait
for another connection request.
The driver also sends a NAK when it receives an STX while it is not ready.
The 3964R procedure appends a Block check character to safeguard the
transmitted data. The BCC-Byte is calculated by means of an XOR function
over the entire data of the message, including the DLE/ETX.
When a BCC-Byte is received that differs from the calculated BCC, a NAK
is transmitted instead of the DLE.
If two stations should simultaneously attempt to issue a connection request
within the QVZ then the station with the lower priority will transmit the DLE
and change to receive mode.
The driver duplicates any DLE-character that is contained in a message,
i.e. the sequence DLE/DLE is sent. During the reception, the duplicated
DLEs are saved as a single DLE in the buffer. The message always
terminates with the sequence DLE/ETX/BCC (only for 3964R).
The control codes : 02h = STX
03h = ETX
10h = DLE
15h = NAK
Timeout times
Passive operation
Block-Check-
character
(BCC-Byte)
Initialization
conflict
DLE