Siemens SIMATIC TIWAY 1 Manual de usuario descargar pdf (Pagina 179)

USING THE NON-INTELLIGENT TERMINAL PROTOCOL

UNILINK HOST

ADAPTERA–3

USER MANUAL

A.1.2 Message

Delimiters

colon ( : )

marks the beginning of a message and a semicolon ( ; ) marks the end

of a message. Any characters between a colon and the next semicolon are

interpreted

as a valid message, while any characters between a semicolon and

the

next colon are ignored.

This allows the host to use any parameters required

its software between lines

of output. When transmitting data to the host, the

UNILINK Host Adapter sends carriage return and line feed characters after

the terminating semicolon, to scroll the response on ASCII terminals. More

intelligent

host devices can be set to filter out the carriage return and line feed.

A.1.3 Character

Count

aid in error control, the colon at the beginning of the message is followed by a

four-character count field representing the total number of printable

characters

the message, including the colon, character count, message body

error checking code, and the terminating semicolon. The four characters

represent

a 16-bit hexadecimal value such that

a count of 100 characters will be

represented

as 30 30 36 34 (0064 hex). NITP messages are limited to a maximum

length

of 590 characters.

A.1.4

Message Body

The message body consists of ASCII character pairs, from the character set in

Table

A–1, representing a single binary byte value. The binary values from each

character pair is the adapter command string discussed in Chapter 2 and

Chapter

5. The maximum message body length is 580 characters.

1 2 ... 174 175 176 177 178 179 180 181 182 183 184 ... 207 208

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Siemens SIMATIC TIWAY 1 Manual de usuario Pagina 179