Siemens SIMATIC TIWAY 1 - Manual (Page 86)

UNILINK HOST ADAPTER 5–1
USER MANUAL
CHAPTER 5
HOST COMMAND SET REFERENCE
5.1 INTRODUCTION
This chapter presents the syntax for each command. The command syntax
descriptions begin in Paragraph 5.2 and are listed in numerical order (starting
at 00 to FE hexadecimal). The command syntax conventions are defined in
Paragraph 5.1.1. Certain network address values have special meanings and
are described in Paragraph 5.1.3.
Paragraph 5.8 provides a summary of the command syntax including both the
command and response syntax. Paragraph 5.9 provides a list of the command
codes and descriptions, listed in numerical order and Paragraph 5.10 provides a
similar list that groups the commands according to their use.
5.1.1 Command Syntax Conventions
Command
Code
Parameter
#1
Parameter
#2
Parameter
#n
Figure 5–1 Command String Structure
Command strings contain the one-byte command code and may include one or
more parameters as defined by each command’s syntax. All values in the
command string are in hexadecimal notation. The selected host interface
protocol, discussed in Chapter 3, will determine whether the command string is
transferred in binary format or converted to ASCII characters. The following
conventions are used to define the command syntax used in the succeeding
sections:
D The most significant bit, labeled Bit 0, is the left most bit in the byte,
word, or long word.
D All command code numbers are one byte, hexadecimal values and will
always be the first byte in the command string.
D Each letter in a command parameter indicates a nibble (four bits) so
that a:
d byte is represented as aa
d word is represented as aaaa
d and a long word is represented as aaaaaaaa
D Parameters containing more than eight nibbles (long word) are
represented as aaaa...