Once we've got our information together, weíre ready to program the
translator. The configuration process requires a terminal program, such as
HyperTerminal, but I used Crestron's Viewport, as I like it as much as a
terminal program. After connecting to the Input port on the Universal
Translator and starting the terminal program with the correct baud settings,
pressing M after a prompt immediately following plugging power into
Universal Translator allows navigation though a simple menu system by
entering numbers associated with each menu item, and when necessary, numbers
and letters to enter the hexadecimal values of the strings. I won't get into
the specifics of the process, as you can read all about it in the manual.
The reading is pretty dull if youíre not actually using it, unless youíre
just into these kinds of things.
The most pertinent information is that we can have the Universal Translator
perform up to 20 translation operations on input strings to generate
output strings. For most purposes, we simply enter string values for a
particular input (1-20), and then enter the string values we want to output to
the respective output number. This means a single string in for one single
string out. For the sake of the polling operation (described later), the
manual says that the input strings for On and Off notification should be
assigned to 1 and 2 respectively, for reasons I didnít see, but conceded to
On the output menu, we can configure a delay between the output strings, to
provide time for the device connected to the output to finish the last
command before taking the next. This is actually quite useful, as a lot of
equipment will just ignore a command if it was followed too closely by the
But wait, thereís more.
Some devices send notification through their serial ports whenever a given
parameter changes, even if they're not asked. This is preferable in almost
every case. For instance, if the volume goes up, a device may send strings
indicating the current volume. Some devices can, but only if they're
configured to do so. Some devices need to be told to connect via their
serial port before
they'll do anything else. The UT has a provision for these
less than optimal cases. The menu allows a startup string that's sent to
the input port, allowing the UT to give the SSP or
whatever device an initial command, to either enable instant notification
and/or further communication. Should power fail, resulting in an SSP that
might need reconfiguration upon power restoration, the Universal Translator
will reinitialize the SSP or other device on the input port. If the system
needs the input port device to be reconfigured on a more regular basis,
say upon system turn on, power can be supplied to the UT
via a switched outlet, or have power run through a voltage-controlled relay,
or whatever the situation requires. Be creative!
If the SSP or other device on the input port does not send notification of
changes, the Universal Translator also has the ability to poll, or rather
send a string on a regular basis that requests information regarding a
particular state of the input device. For instance, if the SSP doesn't
tell the Universal Translator what input its on when it wakes up or changes
inputs, the UT can simply ask on a regular basis. If the answer
doesn't match the last string that the Universal Translator received and
recognized, it knows that something changed and that the corresponding
output string must be sent. It only sends an output string if something
changed because otherwise it'd be sending a string every time it received a
response to the poll query, every second or so.
The polling frequency can
also be adjusted. However, you only get one polling string, so if you canít
get all the information you need (say you need to poll for both power and
input status) with a single string (either a complete status query, or two
different queries sent sequentially as a single string), youíre hosed.
Thereís also a debugging tool available in the menu, which lets us watch the
input strings actually coming from the connected device (typically the SSP)
with the PC's serial port connected to the output port, and shows them to us
in hexadecimal format (converted to ASCII text so that our terminal program
can show them to us with standard text). As a result, we can check the
actual output vs. what we think we know from the documentation.
Click Here to Go to Part IV.