56
| SERIAL / PARALLEL REMOTE CONTROL
PDM
PDM Operator's Manual Version 2.4a • September 2019
Serial language structure
PDM’s serial remote control language is designed to be easily implemented from any ter-
minal program, macros in most automation systems, or computer programming language.
Requests and responses are standard ASCII characters, based on plain English, using
familiar PDM “front panel” designations whenever possible.
Requests, or messages from the controller to PDM, consist of a number of words, followed
by a Line Feed character
27
<LF>
. Messages are case-sensitive.
Responses are replies from PDM back to the controller. They consist of a single
Result
character, any appropriate
message,
and then
<LF>.
The Result character may be:
!
Indicates command has been received and acted upon
?
Indicates command isn’t understood, or can’t be acted upon
Output Events can be sent by PDM whenever there’s a change in status, such as memory
being filled or buttons being pressed. They’re provided so you can design custom serial in-
terfaces to other equipment. Use the
enable
command (
page 59
) to specify which events
generate a message.
Request syntax
Requests consist of a command (something for PDM to do), usually followed by arguments
(what it should act on), and then the <LF>.
Commands include:
down
Start the event described by <argument>
up
End the event described by <argument>
trigger
Momentary activation of <argument>, same as tapping a button
28
.
get
Returns status of <variable>
help
Returns hints about PDM’s serial language
enable
Turns on Output Event reporting for a specific PDM condition
disable
Turns off reporting for a specific condition
Commands are case-sensitive and must be all lower-case.
Arguments include:
Build
,
Exit
,
Cough
,
Dump
,
Bypass
,
Cue1
through
Cue8
,
Flag1
through
Flag8
Arguments act the same as the identically-named GPIO inputs, described
starting on
page 33
.
You can
enable
or
disable
Output Event reporting for just about every PDM function.
A complete list of valid arguments appears on
page 59
.
27 ASCII
10
(decimal) or
OXOA
(hex). Note that Carriage Return (ASCII
13
) is ignored by the system.
28
trigger
<argument>
<LF>
works the same as sending “
down
<argument>
<LF>
up
<same
argument>
<LF>
”. But it sure is easier.
Summary of Contents for PDM
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