Miyachi LMV1000, User Manual

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8: COMMUNICATION FUNCTION (OPTION)
LMV1000 (G)(E) AIR-COOLED LASER MARKER
8-2 990-541
Conditions that cause NAK
࡮
Checksum is abnormal.
࡮
The specified command does not exist.
࡮
The specified value exceeds the setting range.
࡮
The capacity of the internal RAM is insufficient.
࡮
The specified command cannot be executed now.
(i.e. a Marking start command is sent when the Marker is not ready to mark, etc.)
(2) Communication Procedure
The character code used for RS-232C communications is ASCII text code.
The amount of sent/received data is limited to 512 bytes including STX and ETX bits.
When the transmission error (Parity error, etc.) occurs, the received data is ignored.
ACK and NAK status will only be returned when the data is received normally. An ETX command can be
added to ACK and NAK status signal.
NOTE: When the time interval between data communications exceeds a second (for a given command),
all previous data for that command will be ignored.
PC side STX
Command
510 byte or
less
ETX Checksum
Marker
side
ACK ETX or NAK ETX or STX
Command
510 byte or
less
ETX Checksum
(3) Communication Protocol
The data format for communication is composed of the following elements.
STX
Command
Response
(0–510 byte)
ETX
Checksum
(2 byte)
(only when selected)
1. Transmission Control Code
Transmission control code used for communication
Name Value Contents
STX 0
˜
02 Transmission start
ETX 0
˜
03 Transmission end
ACK 0
˜
06 Acknowledgement. Normal transmission/command
NAK 0
˜
15 Receive error, Abnormal transmission/command