Panasonic minas a4 series Instruction Manual page 285

Transmission Sequence
• Transmission protocol
• In case of RS232
Host
• In case of RS485
Host
Module ID : 0
• Line control
Decides the direction of transmission and solves the contention.
Reception mode... From when the module (host or driver) returns EOT after receiving ENQ.
Transmission mode... From when the module (host or driver) receives EOT after transmitting ENQ.
At contention of transmission and reception... Slave side will enter to reception mode when it receives
ENQ while waiting for EOT after transmitting ENQ, by giving priority to ENQ (of master side).
• Transmission control
On entering to transmission mode, the module transmits the command block continuously and then waits
for ACK reception. Transmission completes at reception of ACK.. ACK may not be returned at transmis-
sion failure of command byte counts. If no ACK is received within T2 period, or other code than NAK or
ACK is received, sequence will be retried. Retry will start from ENQ.
• Reception control
On entering to reception mode, the module receives the transmitted block continuously. It will receive the
command byte counts from the first byte, and continuously receive extra 3 bytes. It will return ACK when
the received data sum becomes 0, by taking this status as normal. In case of a check sum error or a
timeout between characters, it will return NAK.
1) ENQ(05h)
2) EOT(04h)
3) Data block
4) ACK(06h)
(or NAK (15h))
5) ENQ(05h)
6) EOT(04h)
7) Data block
8) ACK(06h)
(or NAK (15h))
1) 81h, ENQ (05h)
2) 81h, EOT (04h)
3) Data block
4) ACK (06h)
(or NAK (15h))
5) 80h, ENQ (05h)
6) 80h, EOT (04h)
7) Data block
8) ACK (06h)
(or NAK (15h))
MINAS-A4
Receiving
data
Transmitting
data
MINAS-A4
Module ID : 1
Receiving
data
Transmitting
data
[Supplement]
283