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AVK3 HOST COMPUTER SYSTEM 1.3 Command Descri pti on D77HEC-51- 030-A 0 1.3- 1 1.3. Command Descrip tion D77HEC - 51-030-A 0 Comm ands can be largel y divided int o t he f ollowing 4 categor ies. C comm and Contr ol comma…
AVK3
HOST COMPUTER SYSTEM
1.2 PanaProtocol and Command Specifications
D77HEC-51-020-A0
1.2-4
AVK3
HOST COMPUTER SYSTEM
1.3 Command Description
D77HEC-51-030-A 0
1.3-1
1.3. Command Description
D77HEC-51-030-A 0
Commands can be largely divided into the following 4 categories.
C command Control command
D command Data command
R command Real time command
A command Acknowledge command
1.3.1 C Commands (C0, C1, C2, C3, C4, C5)
There are 6 types of remote control commands to AVK3, C0, C1, C2, C3, C4 and C5. These commands are
all effective only from the host computer controlling AVK3. C commands cannot be output from AVK3 to the
host computer.
1.3.2 A Commands (A0, A1, A2, A3, A4)
A (Acknowledge) command is a command when the host computer converses with AVK3 to acknowledge
that commands have been mutually received and that there are no errors. This command can be used both
by the host computer and AVK3.
Command to request the next data (A0)
This command shows that the receiver has properly received the data transmitted by the sender, and is
usually used as a command requesting the next data during NC program data transmission.
Data resend request command (A1)
If the data received is not normal, an A1 command is returned to the sender. When the sender receives the
A1 command, it becomes data resending mode. Data resending is to send again the data which was in error.
There are the following 6 types in data receiving error.
Framing error
Stop bit is not detected after data character.
Overrun error
The received data is sent within Z80 data buffer and the next data is received before the CPU can
be read by Z80B.
Parity error
There is parity error (even parity check) in the data received.
Check sum error
The figure of the check sum code of the data column received is wrong.
Overflow error
Receiving buffer overflow has occurred.
Format error
No STX or No ETX in the data received.
STX
A 0
No. of
characters
0 2
ETX
Check sum
2D
AVK3
HOST COMPUTER SYSTEM
1.3 Command Description
D77HEC-51-030-A 0
1.3-2
From above contents, A command becomes the following configuration.
∗ Applicable code
0: Framing error 3: Check sum error
1: Overrun error 4: Overflow error
2: Parity error 5: Format error
Even if AVK3 receives error codes E00 - E05, it has no means of expressing it, and does not process them.
Therefore, when the host computer sends the A1 command to AVK3, only A1 is sufficient, and there is no
need to add E00 - E05. (It does not matter if they are added.)
However, from AVK3 to host computer, E00 - E05 data is always added and sent. The host computer is then
able to determine the type of error using that data.
The data resending sequence is as shown in Ex.) and this sequence is exactly the same of whatever data is
being sent.
When AVK3 operation thereafter is continued. If resending is not successful, try to prevent the host
computer from sending the A1 command twice.
As a result, AVK3 discontinues the receiving mode by time out processing, and prepares for the next
conversation.
At the time of resending data, the reason the A1 command is not resent is that it is meaningless to resend it
again.
When A1 command is returned at this time, AVK3 becomes re-resending mode.
If an A1 command is returned from AVK3, the host computer should control the number of A1 commands,
and after resending data only once, discontinue resending.
STX
A 1
ETX
Check sum
E 0 *
No. of
characters
0 5