Yokogawa JUXTA VJ Series Limit Alarms Instrukcja Użytkownika Pobierz pdf (Strona 42)

5-2

IM 77J01J11-01E 3rd Edition : Oct. 15, 2007-00

5.1.1 Configuration of Message

Messages sent from the higher-level device to the VJ Series consist of the following ele-

ments.

Number of bytes in RTU mode None

Number of bytes in ASCII mode 22

(1) (3) (4) (5)(2) (6)

Element Address

Number

(ADDRESS)

Function CodeStart of

Message Mark

Data Error Check End of

Message Mark

None

1224n

1 1 2n 2

050103E.EPS

(1) Start of Message Mark

This mark indicates the start of a message. Note that only ASCII mode requires a

colon (:).

(2) Address Number (1 to 99)

Address numbers are used by the higher-level device to identify the VJ Series signal

conditioners at the communication destination. (These numbers are identification

numbers specific to individual VJ Series, which are expressed in a hexadecimal in the

message.)

(3) Function Code (See subsection 5.2.1, “List of Function Codes”)

This element specifies a command (function code) from the higher-level device.

(4) Data

This element specifies D register numbers, the number of D registers, parameter

values, or others in accordance with the function code. (It is expressed in a hexadeci-

mal in the message.)

(5) Error Check

In RTU mode Carried out by the cyclic redundancy check (CRC-16) system.

In ASCII mode Carried out by the longitudinal redundancy check (LRC) system.

(6) End of Message Mark

This mark indicates the end of a message. Note that only ASCII mode requires CR +

LF.

1 2 ... 37 38 39 40 41 42 43 44 45 46 47 ... 59 60

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Yokogawa JUXTA VJ Series Limit Alarms Instrukcja Użytkownika Strona 42