Command Reference - NEC MultiSync XP29, XM29 Plus User Manual

Command reference

You can control the main functions from external equipment such as personal
computer using the PC/EXT CTL terminals. The following sections explain the
interface.
Interface Condition
• RS-232C
• Baud rate ------------------------- 9600 bps
• Data length ----------------------- 8 bits
• Parity ------------------------------- Odd parity
• Stop bit ---------------------------- 1 bit
• Communications mode -------- Full duplex
Command Communication Sequence
When external equipment such as a personal computer gives the command to
the XP29 Plus/XM29 Plus, the XP29 Plus/XM29 Plus returns an ACK. So
make sure that the external equipment receives this ACK.
Command sending/receiving sequence
External equipment
(PC)
The XP29 Plus/XM29 Plus returns an ACK if it has received the command
correctly.
If it has not received the command correctly due to data error, it will return
nothing. Therefore, when the external equipment send a command, make
sure that it received the ACK.
Command
XP29 Plus/XM29 Plus
ACK
Control Data Format
8bit 8bit 8bit 8bit
Command 2
UNIT ID
Command 1
Command 1 ........ Code based on the command system
UNIT ID ............... Code allocated to each equipment (Allocate 80H to the
XP29 Plus/XM29 Plus)
Command 2 ......... Code allocated to the main functions of the XP29 Plus/XM29
Plus
Data Length ........ Number of bytes of the data that is transmitted
Data .................... Data transmitted
Check Sum ......... Lower eight digits of sum total of the first byte to the byte
immediately before the last.
8bit 8bit 8bit 8bit
Check Sun
Data
Data length
45
46