MacFi-se · MP3 digital audio record/play system with SD card memory, RS-232 control, USB file transfer and sync relay

Overview

The MacFi-se is an MP3 digital audio record/play system for industrial use, with up to 99 messages and hours of MP3 audio on an internal SD card (17 hours or more on 1 GB, by the manual; the spec sheet gives 30 hours or more on 2 GB). The non-volatile memory keeps the messages without battery backup. Messages are recorded from a microphone or line source with the controls on the unit, loaded from a USB memory key, or transferred and controlled over RS-232. Eight messages start from terminals; all 99 are reachable from the front panel and the serial port.

Four playback modes (standard, play once per closure, play while active, re-trigger) let it work with existing on-site control circuitry, with selectable repeats and delay between messages. A built-in 4 W power amplifier drives a speaker directly. Small, industrially built and without moving parts, it suits automatic unattended operation, even in harsh environmental or mobile conditions.

• Records MPEG 1 Layer 3 (MP3) at 128 kbps; plays MP3 at 32 to 320 kbps, VBR, and 16 bit, 44.1 kHz WAV.
• Up to 15 kHz bandwidth (50 Hz to 15 kHz), 80 dB dynamic range and signal to noise, THD below 0.5% at 1 kHz, typical.
• Wall or table mount (rubber feet included); optional 1U rack mount adapter.
• Optional accessories: 12 VDC, 1 A power pack (115 V, 50/60 Hz), rack mount kit, RS-232 cable, CS4 weather resistant speaker with mount, MS-2 microwave motion sensor, ICM-25 input control module (25 start inputs to RS-232), USB memory key.

Installation

• Choose a place on a wall or table; for table top use, fit the rubber feet. Leave about 6″ in front of both sides of the unit for access to the controls and wiring.
• Mount the unit with its wiring at least 18″ away from power supplies or other equipment that generates electrical noise.
• Set the DIP switches, connect the audio inputs and outputs, then the control inputs and outputs.
• With the optional power supply, use a standard, non-switched electrical outlet. Connect and apply power; the unit runs a self test (about 2 seconds) and enters idle mode. Then test its operation.

Connections

• POWER: two terminal pluggable connector; 1, +12 VDC at 1 A; 2, ground. 1 A with the power amplifier in use, 250 mA without. The green POWER LED is on when power is supplied and the system is OK.
• RS232: three terminal pluggable connector; 1, receive; 2, transmit; 3, ground.
• CONNECTOR 1 (12 position pluggable terminal strip): 1, common for all inputs; 2 to 9, START 1 to START 8, connect to common to play messages 1 to 8; 10, STOP, connect to common to stop playback or recording; 11, PLAY RELAY common; 12, PLAY RELAY normally open. Inputs take a mechanical contact or an open collector driver, 3 mA activation current.
• CONNECTOR 2 (3 position terminal): 1, RECORD input, connect to common on Connector 1 to enter record setup mode; 2, SYNC RELAY common; 3, SYNC RELAY Form A contact, closes to 2 when activated.
• Play and sync relays are dry contacts rated 1 A at 24 VDC, non-inductive load.
• AUDIO IN: LEVEL potentiometer, record level, +4 dBm max. input; MIC, mono 1/8″ mini jack, up to 1.5 kΩ, low impedance, compatible with most consumer grade microphones; LINE, mono RCA, 10 kΩ, for the unbalanced outputs of tape decks, CD players, DAT players and the like. Mic and line cannot be used at the same time: disconnect the line input to use the microphone.
• SYNC IN: line level RCA input, 10 kΩ, with an audio sensor that detects tones of 100 ms, for automatic sync track encoding.
• AUDIO OUT: LEVEL potentiometer, playback level, continuous from −∞ to +4 dBm; LINE, mono RCA, 600 Ω, transformer isolated, for the unbalanced inputs of most audio equipment; SPKR, bridged mono speaker output, 2 position terminal, 4 W into 8 Ω or 6 W into 4 Ω. Never reference either speaker terminal to ground: it causes incorrect operation and may damage the unit.
• USB INTERFACE: Type A connector on the front, for a USB memory key.

Configuration switches

An 8 position DIP switch on the back sets the operation (up is OFF, down is ON). It is read only at power up; to change a setting, disconnect power, set the switch and reapply power. The settings marked as configurable over RS-232 take the value set by serial command.

• Switches 1 and 2, number of plays per activation from the remote terminals (for ambient noise or clarity, global for all messages): OFF OFF, once; OFF ON, twice; ON OFF, three times; ON ON, four times, or 1 to 99 times as set with the PLS command.
• Switches 3 and 4, pause between plays: OFF OFF, 1 second; OFF ON, 5 seconds; ON OFF, 10 seconds; ON ON, 30 seconds, or 0 to 99 seconds or minutes as set with the PAS command.
• Switches 5 and 6, play method: OFF OFF, standard operation; OFF ON, play one sequence per closure; ON OFF, play while active; ON ON, re-trigger. A sequence is the message, its number of plays and the pause between plays.
• Switch 7, Play Next: ON lets START 8 (Connector 1, terminal 9) play the next valid message sequence, starting with message 1 after power on; all play methods apply, and START 1 to 7 are disabled.
• Switch 8, Memory Protect: OFF enables recording; ON locks the message memory against accidental overwriting.

Play methods

• Standard: a momentary closure on a START input plays one sequence of its message. A maintained closure repeats the sequence until released, then finishes the current sequence. With several inputs held, the first message plays, then the others in the order they were activated; at exactly the same time, the lower input number wins. A momentary closure released while a message is playing is ignored.
• Play one sequence per closure: a maintained input plays the sequence only once; the input must go inactive for 100 ms before it is recognized again, while other inputs are served normally. Momentary activations are queued and played in the order received, up to 16 sequences including the one playing, and a message may be queued more than once; further activations are ignored. STOP ends the current message, and the next in the queue plays when STOP is released.
• Play while active: the message plays as long as the input is held and stops at once when it is released; a sustained input starts another sequence. With several inputs held, only the active message of highest priority plays and repeats. No queuing.
• Re-trigger: a new activation, of another message or the same one, interrupts the message playing and plays the new one. A maintained activation plays the sequence once. With simultaneous activations, the lower numbered message of the highest priority plays. No queuing.

Controls and indicators

The push buttons, status LEDs and the two digit message number and status display are on the front panel, convenient for rack mounting.

• OVERDRIVE indicator (red): on when the input overdrives the system and the audio clips; reduce the AUDIO IN level until it stays off while recording.
• AUDIO SENSE indicator (green): on when an input signal is present at a good level; adjust the level so it lights while recording.
• RECORD indicator (red): blinking in record setup mode; on while recording.
• SYNC indicator (yellow): on when the sync signal is active, from SYNC IN or the MANUAL SYNC button during recording, and during playback at the points set while recording.
• RECORD SETUP button: enters or leaves record setup mode; no effect during recording. If recording fails, check that Memory Protect (switch 8) is OFF.
• START/STOP button: starts or stops recording or playback of the selected message and returns to idle.
• SELECT button: steps through the message locations for recording or playback; held, it steps by tens.
• MANUAL SYNC button: stores a sync pulse in real time while recording; held while idle, it shows the current baud rate.
• Display: 1 to 99, message playing or recording; all segments cycling, no messages recorded; both decimal points blinking, location occupied; right decimal point solid, the delay, pause or repeat has been set over RS-232; FC, bad block memory test; Hi or Lo, serial port at 115,200 or 9,600 baud.
• Holding START/STOP during power up restores the default DLY, PAS and PLY settings and the 9,600 baud rate.

Recording and playing from the panel and terminals

• Record locally: press RECORD SETUP (the RECORD LED blinks), choose the location with SELECT, listen to the source at the audio output and set the level with the AUDIO SENSE and OVERDRIVE LEDs, press START/STOP and start the source, then press START/STOP to end. Record setup times out after 1 minute of inactivity.
• Record remotely, messages 1 to 8: hold the RECORD input (Connector 2, terminal 1) to common (the RECORD LED blinks), hold the message’s START input to common and start the source; release START to stop recording, then RECORD to leave record mode.
• Play locally: choose a message with SELECT, which steps only through valid recordings (the default is the first valid one), and press START/STOP; press it again to stop. The selection times out after 1 minute.
• Play remotely, messages 1 to 8: a momentary or maintained closure between a START input (Connector 1, terminals 2 to 9) and common (terminal 1) plays the message with the set repeat and delay; a closure on STOP (terminal 10) ends it. An input for an empty or corrupt location is ignored. The play relay is held for the whole sequence and drops for about 100 ms between sequences.
• Memory clear/test: remove power, hold RECORD SETUP while restoring power until the RECORD indicator stays on, then release it. The display reads FC while the audio memory is checked or the SD card formatted, which can take several minutes; the unit is ready when the RECORD indicator goes off. Removing and reapplying power bypasses the test.
• To erase a single message, record a message shorter than 1 second into its location.

Loading audio files from a USB key

The MacFi-se copies audio files to or from a USB memory key according to the folder in the key’s root folder. If more than one of these folders is on the key, nothing is transferred and an error is shown.

• Complete: all files on the MacFi-se are deleted and replaced with the audio files of this folder.
• Delta: files of the same name are replaced and new ones added from this folder.
• Upload: on a key with only an empty Upload folder, all audio files of the MacFi-se are copied into it.
• File formats: WAV (44.1 kHz, 16 bit) or MP3 (44.1 kHz, 32 to 320 kbps, VBR), from a couple of seconds to several hours long. Mono or stereo; only the left channel plays.
• Name the files by message number, 1.mp3 or 1.wav to 99.mp3 or 99.wav; numbers above 99 are ignored, and when an MP3 and a WAV file share a name, the MP3 plays.

RS-232 serial port

The serial port lets the unit be controlled manually or automatically with ASCII commands, for a local user or controller over a short, reliable link; no error detection is implemented. It runs at 9,600 (default) or 115,200 baud, 8 data bits, 1 stop bit, no parity, no flow control. When connected, the unit answers with the MFI> prompt; every command ends with a carriage return ().

To toggle the baud rate, remove power, hold MANUAL SYNC and reapply power: the display shows Lo (9,600) or Hi (115,200). Repeat to change it again.

With a terminal program such as Windows HyperTerminal: choose the serial port (e.g. COM 1), 9600 bits per second (or 115200), 8 data bits, no parity, 1 stop bit, no flow control, and press Enter for the MFI> prompt. To load a file, send DLD with the message number; when “C” characters appear, send the file with the Ymodem protocol.

A voice quality MP3 file can be made with Windows Sound Recorder (MPEG Layer-3 format, e.g. 32 kbps, 44,100 Hz, mono, saved with the .MP3 extension); for full fidelity use commercial ripping or editing software.

RS-232 commands

• PLY message,repeat,pause: plays a message (1 to 99) a number of times (1 to 99) with a pause between repeats (+1 to 99 seconds, −1 to 99 minutes); e.g. PLY6,10,+5. Messages in quotes, such as "1,2", play as one message, up to eight. Without a message number the next available message plays (message 1 after power up); without repeat it plays once; without pause the pause is 1 second. PLY commands sent during playback are queued.
• REC message,delay,time: records into a location (1 to 99) after a delay of 1 to 99 seconds, for a time of 1 to 99 seconds (+) or minutes (−); e.g. REC8,10,-4. The location is erased at once, any message playing stops, and the input is routed to the output for monitoring; recording starts after a 1 second delay and ends with STP, the time limit or the end of memory, keeping what was recorded. Without a number it records into the first free location; REC alone records from a 1 second delay to the end of memory. Disabled messages may be overwritten.
• STP: stops playback or recording and clears the message queue.
• DLD message: receives an MPEG 1 Layer 1, 2 or 3 (MP3) file by YMODEM, up to 128 kbps, into the location or, if left blank, the next empty one. ULD message: sends a message to a controller or computer by YMODEM.
• PLS 1 to 99: plays per trigger (default 1), replacing switches 1 and 2. PAS ±1 to 99: pause between play repeats, + seconds, − minutes (default 0), replacing switches 3 and 4. DLY ±1 to 99: delay before the first play (default 0). These three apply to starts from Connector 1.
• PRI message,E or D: enables or disables a message; a disabled message does not play from the sequence or from PLY. DIR: lists the 99 locations, a number for a valid message, XX for an empty one, D before a disabled one. DEL message: deletes a message.
• BAS and TRE 0 or −6 to +9: bass and treble level in dB (default 0).
• STS 1 or 0: turns on or off the status messages sent to the port when a message starts or stops, for controlling other systems.
• CFG: restores the default settings (such as PAS and PLS) and 9,600 baud. SHP: formats the memory card, erases all messages and resets every setting to factory default, ready again within about 10 seconds. BBT: memory bad blocks test, formats the internal SD card and erases all audio; done when the MFI> prompt returns. RST: warm reset. SYS: diagnostic system information. LST: lists the commands. BBT, CFG, DEL and SHP ask for Y/N confirmation.

Synchronization

The sync relay can be programmed with up to 100 outputs per message location, automatically or manually, and closes at the same points of the message on every playback. Sync pulses must last at least 100 ms and be at least 100 ms apart.

• Automatic: while recording, each tone detected at SYNC IN stores a 250 ms sync pulse; on playback the sync relay (normally open) closes at that point.
• Manual: while recording, each press of MANUAL SYNC stores a 250 ms sync pulse, played back the same way.
• The SYNC indicator lights at each pulse, during automatic and manual programming and during playback.