Black Box 945 - Manual (Page 11)

11
WATLOW Series 945 How to Use Data Communications
Syntax
Message Syntax
Messages from your computer to the Series 945 must take this general form. All
commands do not require the full number of data fields.
Command <Space> Data.1 <Space> Data.2 <Space> Data.3... Data.N
"Command" is a character set to which the Series 945 will respond. The brackets
"< >" enclose a non-literal description. "Space" is simply a delimiter, an ASCII
space character (Hex 20). "Data Fields" are parameters and values specific to a
command; the number of possible data fields depends on the particular command
you use. Data 1 is here abbreviated, "Data.1", Data 2 is "Data.2" and so on.
In the syntax explanations ahead, we'll show you the specific arguments for each
command. It will speed the process, if you remember this general syntax.
Data Rules
Data fields are parameters and values specific to particular commands. These rules
govern their use. Specific data for each command is listed later in this chapter.
• Data will be ASCII 0 through 9, unless otherwise noted.
• Data can go up to seven total characters, including a minus sign. A + or - sign, if
used, must be first, and it must have a decimal point if applicable.
• Data can use leading zeros. (Up to 7 digits.)
• Data does use decimal points.
• Data.1 portion of message can be up to four total characters.
Series 945 General Message Syntax
As soon as you link the devices, you'll be able to talk to the Series 945 using ASCII
characters.
The Series 945 will respond to any Operating or Setup parameter, plus some
others. The control will respond to either upper or lower case ASCII characters
from your computer.
Both protocol/interface combinations will respond to the general syntax, providing
the commands or queries are correctly transmitted. However, the ANSI X3.28
Protocol requires beginning and ending characters, and the XON/XOFF Protocol
requires ending characters. We'll look at those shortly.
Command List
These commands, represented by their respective ASCII characters, will enable
you to program the Series 945 from your computer. More detailed descriptions of
the commands are on the pages noted.
? Finds the value of a specific parameter. p. 19
= Sets a specific parameter to a specific value. p. 20