Chapter 3: Software
General
The RDAG12-8 comes with ASCII-based software provided on CD. ASCII programming permits
you to write applications in any high-level language that supports ASCII text string functions,
allowing the "REMOTE ACCES" series modules to be used with virtually any computer that has an
RS485 port.
The communication protocol has two forms: addressed and non-addressed. Non-addressed protocol
is used when only one REMOTE ACCES Pod is to be used. Addressed protocol must be used when
more than one REMOTE ACCES Pod is to be used. The difference is that an address command is
sent to enable the specific Pod. The address command is only sent once during communication
between the specific Pod and the host computer. It enables communication with that specific Pod
and disables all other REMOTE ACCES devices on the network.
Command Structure
All communication must be 7 data bits, even parity, 1 stop bit. All numbers sent to and received from
the Pod are in hexadecimal form. The factory default baud rate is 9600 Baud. The Pod is considered
to be in addressed mode any time its Pod address is not 00. The factory default Pod address is 00
(non-addressed mode).
Addressed Mode
The address select command must be issued before any other command to the addressed Pod. The
address command is as follows:
"!xx[CR]" where xx is the Pod address from 01 to FF hex, and [CR] is Carriage Return, ASCII
character 13.
The Pod responds with "[CR]". Once the address select command has been issued, all further
commands (other than a new address select) will be executed by the selected Pod.
The addressed
mode is required when using more than one Pod.
When there's only one Pod connected, no address
select command is needed.
You can merely issue commands listed in the following table. Terminology used is as follows:
a.
The single lower case letter 'x' designates any valid hex digit (0-F).
b.
The single lower case letter 'b' designates either a '1' or '0'.
c.
The symbol '±' designates either a '+' or a '-'.
d.
All commands are terminated with [CR], the ASCII character 13.
e.
All commands are not case-sensitive, i.e., upper or lower case may be used.
f.
The symbol '*' means zero or more valid characters (total msg length<255 decimal).
General Note:
ALL numbers passed to and from the Pod are in hexadecimal.
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Manual MRDAG12-8H.Bc2