DMR-PD-008 · Multi-channel random access digital message repeater for alarm and life safety systems

Installation and power-up

The DMR-PD-008 is a solid state, user programmable, multitrack digital audio message repeater for announcement applications, in an 18 gauge cold rolled steel enclosure of 12 × 12 × 2.5 inches with six notches for wall mounting. It holds 16 messages and four audio channels and can play any message through any output at any time.

With the power off, wire the power to the pluggable terminal strip. Connect the earth ground terminal to the alarm panel’s earth ground; it gives the control inputs their transient (lightning) suppression, and without it a large voltage spike can damage them. At power-up the unit checks its internal workings, loads its saved configuration (memory map, DIP switch positions and the settings made through the serial port), then self-checks the inputs, audio channels and memory. It then lights the SYS OK LED and energizes the failure relay to show that it works properly. This takes one to two seconds, and commands given during it are ignored.

• Power 24 VDC ±10 %; the internal regulators accept any clean supply from 15 to 30 V. Current 150 to 250 mA idle, 250 to 500 mA running, 1 A maximum at startup.
• Expansion boards (audio channel boards for channels 2 to 4, a second memory board for messages 9 to 16) are installed by the factory when ordered with the unit, by the user otherwise. Power the system down before working on it, adjust the DIP switches when adding audio channels, and rebuild the memory map with the BLD command after adding or changing memory chips.
• Operating temperature 0 to 50 °C.

Connections

• 50-pin ribbon connector: primary port for system control and status, typically wired with 26 gauge solid wire. The optional RC-3 interface board breaks each wire out to a screw terminal.
• 5-position Euro style connector (lower right side): +24 V, ground, earth and the audio output of channel 1. It takes 26 to 14 gauge wire; do not overtighten the screws.
• 2-position Euro style connectors (lower side): audio outputs of expansion channels 2 to 4.
• RJ11-6 modular jack: RS-232 serial link, on the center pair. Use six-pin modular plugs and cable only; four and two pin plugs can sit wrongly in the jack.
• RCA jack: line level input for units with field recording; 600 Ω, transformer isolated, designed for 0 dBm.
• 3.5 mm mini-jack: microphone input for units with field recording, for an off the shelf low impedance microphone.
• Audio outputs: each drives a 600 Ω load at up to +4 dB, preset at the factory and adjustable in the field.

Control inputs

All inputs on the 50-pin connector are active low. An unused input sits at 5 VDC; to activate it, ground it to system ground (position 26) through a switch, a relay contact or an open collector driver able to sink 10 mA at 5 V, and hold it at least 100 ms. The inputs are directly coupled, with high speed transient suppression.

• Start Message 1 to 16 (positions 9 to 24): play the message through its default audio channel; each message defaults to channel 1 unless another channel is given when it is recorded.
• Channel Select 1 to 4 (positions 2 to 5): held about 50 ms before a Start and maintained, they route the message to the selected channel instead of its default one. With several selected, the message plays on all of them at once; a busy channel queues it by order of arrival and priority.
• Stop (position 6): halts the playing messages on every channel and clears every queue; typically used to reset the system from an alarm condition.
• PLI, Play Immediate (position 7): held with the channel select before a Start, it gives the message priority 9. It stops any playing message of lower priority and plays at once; the interrupted message then plays again from its beginning. Messages otherwise have priority 1, changeable through the serial port.
• Record (position 8, optional): starts and stops a recording on units with on-site recording.

Status outputs and indicators

Status is given by front panel LEDs and dry, isolated relay contacts rated 1 A at 24 VDC, non-inductive load.

• System Failure: active (common shorted to the normally open contact) during normal operation, deactivated on an error that could affect operation, such as a CPU failure, a missing or bad message chip or the failure of all audio channels.
• System Active: active while any audio channel is busy, through message plays, pauses and delays.
• SYS OK LED: lit while all systems are OK, out on any problem.
• Playing 1 to 4: relay contacts and a green LED per channel, active while that channel plays.
• Error Channel 1 to 4: form A contact and a red LED per channel, active when that channel fails during a play or self-check. A failed channel plays nothing until the fault clears; output levels set too low, or a load under 600 Ω such as a speaker or headphones without an amplifier, can cause an audio sense failure.
• LOCK, REC and PGM LEDs: recording status, on units with on-site recording.

RS-232 control

Most of the complex control is available only through the RS-232 link, WYSE 50/100 emulation at 9600 baud, 8 data bits, 1 stop bit, no parity. When connected, a system prompt appears and commands are typed on the keyboard; each is three characters followed by its parameters.

• PLYa,b,c,d: play message a through channel b, c times, with a d second pause between plays (PLY6,4,10,5 plays message 6 on channel 4 ten times with 5 s pauses). Without b the message plays on channel 1; without c or d the global PLS and PAS settings apply.
• PLI: like PLY, but stops the message playing on the selected channel, puts it back in the queue and plays this one at once.
• STP stops the playing messages on all active channels; STPALL also clears every queue.
• PLS (1 to 15): plays per activation, default 1. PAS (0 to 127): pause between plays, default 1 second. DLY (0 to 127): delay before play, for example to let an external tone generator precede the message.
• MAP lists which of the 16 message positions hold a message. BLD rebuilds the memory map after a message is inserted or removed; the unit fails on any unexpected change in its memory.
• ATT on/off: auto test of memory, audio channels and general functions. ARS on/off: automatic restart, clearing an error after one minute. VCK on/off: VoiceCheck of the audio channels during the self-test, before each play and during play.

DIP switches

The DIP switches set the default global settings. After changing them, press the reconfiguration pushbutton (on the side with the switches, the one farthest from them), then the Reset pushbutton; every setting programmed into the unit is replaced by the switch settings.

• Bank A, 1A/2A, plays per activation: on/on 1, on/off 2, off/on 3, off/off 4.
• Bank A, 3A/4A, pause between plays: on/on 1 s, on/off 3 s, off/on 5 s, off/off 10 s.
• Bank A, 5A/6A, delay before play: on/on 1 s, on/off 3 s, off/on 5 s, off/off 10 s.
• 7A on: VoiceCheck (VCK) off. 8A on: auto test (ATT) off.
• Bank SW2: 1 on, automatic restart (ARS) off; 2 on, input supervision off; 3 and 4 on, CD3 and CD4 off; 5 to 8 on, audio channel 1, 2, 3 or 4 disabled.

On-site recording (option)

With FLASH EPROM memory, chosen at the time of purchase (units without it cannot be upgraded in the field), users record their own messages. A key switch protects the messages from being overwritten or erased by accident. The microphone and line inputs cannot be mixed; watch the line level, as a level much above 0 dBm distorts and a low level sounds noisy.

• Insert the key and turn it fully clockwise; normal operation stops. Start the audio source and activate the Record input; the recording runs while the input is active.
• Release Record; the new audio plays back at once. Listen to the whole playback for distortion or noise.
• If it is acceptable, turn the key to the center position, then activate the Start input of the message position to fill, holding a Channel Select first to give the message a default channel other than 1. The record LED blinks slowly while the message is burned into memory.
• Turn the key fully counterclockwise to return to normal operation; the new message plays from its Start input. Turning the key there before the burn starts aborts the recording and erases it from the cache. If no FLASH chip sits in the selected position, nothing happens.

Troubleshooting

• No LEDs lit → check that the DC power is plugged in and present on the cord, that any power strip is switched on, and that the LED board is connected.
• Fail contact opens during operation → check the relay wiring and the stability of the input voltage, that no audio outputs are shorted together, that no message was added or removed without rebuilding the map (BLD), and whether input supervision is active.
• Messages do not start (Play relay inactive) → check the relay wiring and the System Active LED, measure 0 V between the start input and the input common, make sure the message is in memory and that Stop is not active.
• Message starts but no audio (Play relay active) → turn the audio level potentiometer up (clockwise), verify the audio output wiring and listen to the right channel.
• No response on RS-232 → check the power LED and the protocol (9600 baud, 8 data bits, 1 stop bit, no parity), and put a null modem between the unit and the communications port.
• Will not record (Lock and Rec LEDs off) → check the power LED, that the key is inserted and turned fully clockwise, and that the Record input is active (0 V between it and the input common).