PORTABLE MODEM USER’S GUIDE

This Time Code Modem represents the latest Design, 202 FSK External Time Code Modem from Pyrodigital Consultants.  This Modem is designed for use with fixed location office Scripting Computers as well as for use on the road with Portable Scripting Computers.  The Modem is powered either from the AC Mains (through a transformer wall pack), or via it’s own standard 9 volt battery.

The Pyrodigital Time Code Modem’s function is to read (and generate) Pyrodigital Time Code.  Pyrodigital Time Code was developed by Pyrodigital Consultants for use with Starlight Systems and Pyrodigital Scripting/Choreography Software, as well as Pyrodigital Firing Hardware.   The Modem Unit serves as a link between the digital world of computers and the analog world of everyday audio tape machines.  The Time Code thus serves to link the Music (on a separate audio track) to the Choreography and/or Firing Computer in a transparent and automatic fashion.

NOTES ABOUT PYRODIGITAL TIME CODE:

Pyrodigital Time Code is a very “bullet proof” Time Code in that it may be tape copied many times without incurring problems or difficulty in the ability to read (or recover) the Time information.  Also the Pyrodigital Time Code may be transmitted over a restricted bandwidth, such as voice grade telephone lines, high frequency attenuating hard line transmission systems, MARTY transmitters with reception on simple “Scanners”, or other media.  The required bandwidth is only ap­proximately 100 Hz to 2500 Hz (1200 Baud FSK).  (The Time Code will not transmit / recover satisfactorily over voice radios which use a REPEATER or through Sampling Frequency Conversion of a Digital Recording).   OBVIOUSLY, TEST YOUR INTENDED TRANSMISSION SYSTEM.

The Pyrodigital Time Code is a “smart” Time Code, in that each Time number data block is a distinct and unique time number, every 1/10 of 1 second.  This means that the correct Time can be read at any point within the Time Code.  Thus, unlike conventional FSK (Frequency Shift Keying) Time Code, you do NOT have to start the Time Code at the beginning of the tape.  You simply start the Tape anywhere and the correct time is instantly recovered by the Software Program.  The Pyrodigital Time Code uses a distinct Time number each 1/10 of 1 second for high accuracy.  The Software Program may also interpolate between each 1/10 Time Frame for extended resolution.  The Pyrodigital Time Code also incorporates error checking (parity data bits) to in­sure usage of only valid Time numbers.

Thus, the Pyrodigital Time Code offers all the advantages of SMPTE, plus the additional advantage of being much more resilient or “bulletproof”, plus the ability to be transmitted over a restricted bandwidth.

NOTES ON SMPTE TIME CODE:

PYRODIGITAL TIME CODE IS ABSOLUTELY PREFERRED OVER SMPTE (Society of Motion Picture and Television Engineers) Time Code.  We recommend that you avoid the use of SMPTE Time Code.  SMPTE Time Code is an EXTREMELY fragile Time Code that is not suitable for transmission for more than a few feet by wire cable, without extreme care.  SMPTE requires a full audio Bandwidth of 20 Hz to 20 KHz.  SMPTE should be “regenerated” if it is to be copied to another tape.  SMPTE is easily miss-read or miss-interpreted.  SMPTE contains no built in error checking capability.

The Pyrodigital Time Code Modem will not work with SMPTE Time Code.  Pyrodigital Consultants does offer a CONVERT Software Program which will convert 30 frames per Second, Non Drop, SMPTE Time Code to an ex­act mathematically identical Pyrodigital Time Code.

Pyrodigital Time Code is much better suited to the application and you should emphasize the importance of it’s use to your clients if they suggest SMPTE.

MODEM CONNECTION;

Connection of the Modem Unit is very simple and straightforward.

1)    Install an Asynchronous Serial Communications Card in your Com­puter.  Refer to the instructions provided with the Card or have your dealer install the Card.  Note that your Computer may already have this card installed, or your Card may be upgraded by adding a second COM Port.  Use a Card (or connector harness) with a DB 25 Pin male connector for the easiest connection.  Set the jumpers on the Card for COM1 or COM2, your choice, depending on your System configuration.  Many Computers and COM Cards are equipped with a DB-9 Pin Male Connec­tor for the Serial or COM Port; this is fine also.

2)    Connect the Modem Unit to your Computer with a DB 25 Pin Modem Cable.  The Modem Unit has a DB 25 Pin female connector.  Use a HAYES type Modem Cable with DB 25 Male at one end, DB 25 Pin Female at the other end (assuming your computer Async Card has a DB 25 Pin male connector).  It is not necessary to have a cable with all 25 wires/pins used (a Hayes cable uses Pins 1 through 8, plus 20 and 22).

3)    If you computer has a DB-9 Pin Male COM Connector, then you will need a DB-9 Pin female to DB-25 Pin male SERIAL Cable.  Make sure that you get a SERIAL Cable, as there are several types of 9 pin to 25 pin Cables.  Only the SERIAL Cable has the correct wiring.  IF the Modem doesn’t work, and you are using a 9 pin to 25 pin cable, then you probably have the wrong type of cable.  There are also 9 Pin to 25 Pin SERIAL adapters of various genders available, should you wish to use a 9 Pin Cable and then adapt to the 25 pin Connector on the Modem.

4)    For normal OFFICE COMPUTER use, connect the included wall plug transformer to a master switchable 120vac source and plug in the mini plug connector to the Modem Unit.  NOTE THAT PHYSICAL CONNECTION OF THE MINI PLUG TO THE MODEM AUTOMATICALLY DISCONNECTS THE MODEM INTER­NAL BATTERY FROM THE POWER CIRCUIT.  It is recommended that you con­nect the wall pack transformer to a master computer switching unit (or a simple multiple outlet switch strip) from which you turn on your en­tire computer system.  Thus when you power down your computer, the transformer wall pack will also be powered down.  THE WALL PLUG TRANS­FORMER SHOULD ALWAYS BE DISCONNECTED FROM 120VAC (AC Mains) WHEN NOT IN USE.  (Never leave the transformer wall pack energized when not in use).  Simply switching the power switch on the back of the Modem WILL NOT power down the transformer wall pack.

5)    220vac / 50Hz transformers are available from Pyrodigital Consultants for overseas use.  Note that any wall pack transformer may be used that has a compatible mini plug with at lease 50ma of current and either AC or DC voltage between 9 and 16 volts.  The Modem is DC Polarity compensated so the DC Power to the tip of the mini plug may be of either polarity.  A special FUSED adapter could easily be made, for example, to operate from a automobile cigarette lighter or other external power source. (If making a automobile adapter, be sure to make the ring of the mini plug as ground, lest you have a short when accidentally touching the mini plug to any metal on your car).

4)    There are two RCA Phono jacks on the Modem Unit.  The OUTSIDE most jack, labeled PLAY is for Time Code INPUT and the INNER RCA jack, labeled REC is for Time Code OUTPUT (for RECORDING Time Code to tape).  These jacks are for standard Japanese / American Audio level (-10 db, unbalanced, high impedance).  The input has automatic gain control and can accept levels from -40 db to +4 db.   CONNECT THE MODEM PLAY (outside most) JACK TO THE PLAY OUTPUT OF YOUR TAPE MACHINE AND THE REC (inner most) JACK TO THE RECORDING INPUT OF YOUR TAPE MACHINE.  Use the same tape track for both input and output (ie track 4 on a 4 track, Right for 2 track).

5)    Switch on the Modem Unit by depressing the RED rocker switch, to either PLAY, for Playing the tape, or REC, for recording Time Code.  Note that the Switch on the Modem also has a Center Off Position.  Note also, for convenience, that the outside position of the switch (and the outside RCA jack) are for PLAY. When the Modem switch is in the REC position, the Modem is forced to the “Full Loop Back”  connec­tion.  This directly internally connects the input to the output so that Carrier Detect is enabled and the Modem output “enable” is LOCKED ON.  Without “Full Loop Back”, when attempting to generate Time Code, your Modem Unit will just sit there and not actually generate any Time Code.  “Full Loop Back” may also be established via your audio connec­tions to the tape machine and/or mixer.  In this case you can generate Time Code with the Modem in the Play Position.  See the next section for a discussion of “Full Loop Back”.

 

 

MODEM UNIT OPERATION;

TIME CODE PLAYBACK; Control of the Modem Unit is through the Software Program.  Refer to the Program Manual for Operation with the Pyrodigi­tal Modem Unit.  Normally the usage is automatic, you start the tape (which inputs time code into the computer), and the Program Scripting Screen automatically activates the “Time Window” or other functions.

RECORDING TIME CODE;  Refer to the Software Program Manual for setting up Parameters for recording Time Code.  BE SURE TO SWITCH THE MODEM TO THE REC POSITION.  The recording level may be anywhere from -10vu to 0vu, with -10vu recommended for Cassette Tape Machines, -0vu for Open Reel Tape Machines.  Noise reduction may be used and will not normally interfere with the time code.  If you are having trouble recovering the time code try; 1) cleaning and demagnetizing your tape machine heads, 2) check the bias and equalization settings for the type of tape used, 3) change the recording level (try a lower/higher level), 4) switch off the noise reduction, 5) Be sure Full Loop Back is used and functioning as outlined below (Switch on Modem to REC position) 6) Check / Replace RCA patch Cables.

CAUTION – VERY IMPORTANT

THE MODEM UNIT WILL NOT GENERATE TIME CODE UNLESS A “LOOP BACK” IS ESTABLISHED.  WITH THE PORTABLE MODEMS, LIKE THIS ONE, SIMPLY SWITCH THE RED ROCKER SWITCH ON THE BACK OF THE MODEM TO THE REC POSITION.  THIS WILL INTERNALLY, AUTOMATICALLY, ESTABLISH THE “FULL LOOP BACK” SIGNAL PATH.

NOTE THAT IN THE REC POSITION, THE TIME WINDOW OF THE SCRIPTING PROGRAM WILL BE LOCKED OPEN AND NOTHING IN THE SOFTWARE SCRIPTING PROGRAM WILL FUNCTION.  SWITCH THE MODEM BACK TO PLAY FOR USE WITH THE SCRIPTING PROGRAM.

You can externally establish the “Loop Back” with the modem Red Rocker Switch set in the Play Position, thus relieving you from ever having to change the switch position.  In this case you must establish the “Loop Back” externally as explained below.

Note that an Output signal is always present at the recording output jack.  This is a steady 1200Hz tone (for ease in setting recording level).  Only when this tone is modulated (a distinctly different chirping sound, every 1/10 second) are you actually generating time code.

Thus to generate Time Code you must route the output signal back to the input.  This may be accomplished with a source/monitor switch on your tape deck (do not switch between source / monitor while recording, or you may loose 1 or more frames of time code)

The most straightforward way to connect is to use a “Y” connector at the modem to directly connect the input to the output and MONITOR THE SIGNAL while the Software Program is generating Time Code.   (listen to it through your sound system and see if in fact the 1200 Hz tone is modulated (chirping sound).  As men­tioned earlier, the Portable Modems, like this one, can be simply switched to REC, which accomplishes the same thing as connecting a “Y” connector from the output to the input.

NOTE THAT THE “FULL LOOP BACK” FEATURE (switch to REC) MUST ALSO BE ESTABLISHED TO CORRECTLY DETERMINE THE CORRECTION FACTOR (set up Modem with Full Loop Back and verify that time code is ac­tually being generated (when Software is instructed to generate time code) by monitoring the sound, before attempting to get ex­act correction factor, see the Software Operators Manual for ad­ditional information).

PORTABLE USE:

This Modem is additionally equipped with an internal, replaceable, standard 9 volt battery for Scripting use with battery powered Port­able Notebook or Laptop Computers.  Thus Scripting without access to AC Mains Power is easily accomplished.

The Modem was intentionally designed to use a standard 9 volt battery, as opposed to a rechargeable battery back.  The standard 9 volt bat­tery is very easily obtainable worldwide, and at a minimal cost.  Thus you can continue Scripting by replacing a dead battery, without the necessity of having to find AC Power to recharge.  Since the Modem employs CMOS circuitry, the power draw is extremely small.  Therefore, a standard ALKALINE 9 volt battery will power the Modem for more than 50 hours.  Note that at 2 hours per day, you could script for a mini­mum of 25 days.

THE ONLY DRAWBACK IS THAT YOU MUST REMEMBER TO TURN OFF THE MODEM, or just as with most all other battery powered devices, you will exhaust the battery in a manner of days.

Whenever the transformer wall pack mini plug IS NOT CONNECTED to the back of the Modem unit, power for the Modem Unit will come from an in­ternal 9 volt battery.  If the battery is not installed or the battery is dead, then the Modem will not operate without a power source con­nected to the mini plug.

This also means that when the transformer wall pack is connected, via the mini plug, your battery is not being used up.  So in the case of office scripting, you may leave the 9 volt battery inside the modem AND never bother to switch the Modem off via the Red Rocker Switch.

The Modem will be powered on and off via the master Computer Power Switch which provides power to the transformer wall pack.  Since the mini plug is connected to the Modem, the internal battery will not be used even when the Modem Switch is in the PLAY position.

If you remove the modem from the office environment, be sure to switch OFF the Modem when disconnecting the mini plug from the back of the Modem.

AS LONG AS THE GREEN POWER LED ON THE FRONT OF THE MODEM IS NOT IL­LUMINATED, THEN THE MODEM IS NOT DRAWING ANY POWER FROM ANY SOURCE.

BATTERY INSTALLATION:

USE A STANDARD 9 VOLT (ALKALINE RECOMMENDED FOR LONG LIFE) TRANSISTOR RADIO BATTERY, available worldwide.

WHEN USING THE MODEM FOR OFFICE SCRIPTING ONLY, REMOVE (or do not in­stall) THE INTERNAL BATTERY.  INSTALL THE BATTERY ONLY IF REQUIRED FOR SELF POWERED PORTABLE SCRIPTING USE.

REPLACE THE BATTERY WHEN THE GREEN LED IS DIM OR NOT ILLUMINATED (when the Modem is switched to Play or Rec) OR THE MODEM UNIT FUNCTIONS ER­RATICALLY OR NOT AT ALL.

1)  Remove the 4 screws which hold on the 4 rubber feet on the bottom of the Modem.  Note that you may be able to simply twist the rubber feet (counter clockwise) and remove each screw and rubber foot as one unit.

2)  Carefully slide out the Modem Bracket from the Aluminum Housing.  BE CAREFUL NOT TO TOUCH ANY OF THE ELECTRICAL COMPONENTS OR CIRCUIT BOARD TRACES AT ANY TIME.

3)  Align the battery into the holder with the correct polarity (as marked on the battery, the male snap is always positive), inserting the contact end first.  Pull back on the rear white plastic bracket clamp with your thumbnail and lock the battery into position.  The battery won’t fit correctly if the polarity is reversed.  It maybe easier to use your thumbnail on the front contact end of the battery and insert the rear end of the battery first, or a combination of both techniques.

4)  Slide the Modem Bracket back into the aluminum Housing, noting that the 4 screw holes for the feet are on the bottom of each part.  The Aluminum Housing is Symmetrical, so there is no front or back.

5)  Align the screw holes and replace the rubber feet and screws; finger tight is OK, so that a screwdriver is never required.

6)  Switch On the Modem unit, checking that the Green LED on the front comes on bright for both the REC and Play switch positions.

7)  Be sure to switch OFF the Modem, lest you run the battery dead.  Remove the Battery for extended Storage of the Modem or when not required as with your office scripting Computer (use the transformer wall pack, it’s cheaper than batteries).  Removing the battery will avoid possible battery leaks.

8)  A fresh Alkaline battery should be able to operate the Modem for 50 hours or more.

QUICK POINTS TO REMEMBER:

1)  If the Time Window of the Scripting Software is “Locked Open” then you probably have the Modem switched to the REC Position.

2)  Be sure to have the Modem switched to REC for recording Time Code or checking the “Delay Factor” with the Timegen Software, and MONITOR (listen to) the time code output (to be sure time code is actually being generated).

3)  Be sure to switch off the modem when the mini plug is not connected or you will run your battery dead (NO green light).

4)  Don’t leave a dead 9 volt battery inside the Modem (to avoid poten­tial battery leaks).

5)  The Play position of the switch and the Play jack are always to the OUTSIDE of the modem, so you know which way to switch the switch and which jack to connect without looking.  Also the  narrow width of the DB 25 pin connector is towards the bottom, or as a wide “V” top to bottom.

END

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