YOKOGAWA UT150L, Руководство пользователя

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IM 05C01E22-10E
3-2
3.1.1 Configuration of Command
Commands sent from a host device to UT150L, consist of the following elements.
Number of
Bytes
Element
1
STX
2
Address
number
(ADR)
2
CPU
number
01
1
Time to
wait for
response
0
3
Command
Variable length
Data corresponding
to command
2
Checksum
1
ETX
1
CR
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(1) STX (Start of Text)
This control code indicates the start of a command. The character code is CHR$(2).
(2) Address Number (01 to 99)
Address numbers are used by the host device to identify UT150L at the communication destination.
(They are identification numbers specific to the UT150L.)
(3) CPU Number
This number is fixed to 01.
(4) Time to Wait for Response
This is fixed to 0.
(5) Command (See subsection 3.2.1, List of Commands)
Specify a command to be issued from the host device.
(6) Data Corresponding to Command
Specify an internal register (D register or I relay), number of data pieces, UT150L parameter value,
and others.
(7) Checksum
This converts the ASCII codes of texts between the character next to STX and the character immedi-
ately before the checksum into hexadecimal values and adds them byte by byte. It then fetches the
single lowermost byte of the added results as the checksum.
This column is only required for PC link communication with checksum. PC link communication
without checksum does not require this 2-byte space of ASCII code.
(8) ETX (End of Text)
This control code indicates the end of a command string. The character code is CHR$(3).
(9) CR (Carriage Return)
This control code indicates the end of a command. The character code is CHR$(13).
NOTE
The control codes STX, ETX, and CR are essential for commands when you create a communication
program for PC link communication. Omission of any of them or incorrect order of them results in
communication failure.