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3. Command Line Interface
About this Guide
This chapter lays the groundwork for the communication protocol between client software running on a remote
host and the V750 reader.
3.1 Command Interface
3.1.1 Command / Response Frame Structure
Ethernet and RS-232C has almost the same command structure for command line I/F. Command frame has a
Command Code area to control the R/W and Command Data area that is used with Command Code.
Terminator that indicates the end of the frame is [LF].
RS-232C requires a start code [SOH], check data, and [CR] additionally. The start code shall be at the
beginning of the frame, and the check data and the [CR] shall be just forward terminator [LF].
Command frame for Ethernet
Command frame for RS-232C
Contents in command frame
Contents Description
Ethernet
required
RS-232C
required
Start Code [SOH=0x01] Indicates the beginning of the frame with SOH.
No
Yes
Command Code
Specifies the command the reader executes.
Yes
Yes
Command Data
Specifies the data for use with Command Code
Yes
Yes
FCS
Stands for Frame Check Sequence (hereinafter referred
to as “FCS”. The code is to detect an FCS error.)
The result of the horizontal parity calculation from after
SOH through just before the FCS is expressed by two
characters of ASCII code.
No Yes
Terminator [CR=0x0d]
Indicates the end of the frame with CR.
No
Yes
Terminator [LF=0x0a]
Indicates the end of the frame with LF.
Yes
Yes
Command Code
Command Data
LF
4 Bytes n
1
SOH Command
Code
Command
Data
FCS
CR LF
1 4
n
2
1
1
Terminator
FCS Calculation Range
Terminator