EM34A / EM34A-R / EM34A-X User’s Manual
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Available Models
EM34A: no internal relays.
EM34A-R: 4 relays for simple control.
EM34A-X: 4 relays for advanced control.
Firmware Version
1.4
Technical Specifications
Operation Mode
playback only
Sound File Format
MP3 (ISO 11172-3 up to 44.1KHz)
Max. Number of Sound Files
Direct Mode: 4
Sequential Mode: 4 x 99
Script Mode: 999
Memory Card Type
SD/SDHC
Max. Memory Capacity
2 GB for SD (FAT/FAT16)
32 GB for SDHC (FAT32)
Max. Recording Time
(Assuming 128 kbps on a 2GB card)
33 hours
Supply Voltage
12 ~ 30 VDC
Typical Standby Current
60 mA
Audio Output
(30V supply, 8 Ohm load, 10% THD+N)
High efficiency class D
Stereo: 15W per channel
Mono: 55W bridge tied load (BTL)
Trigger Interface
4 inputs, contact closure or 3.3V/5V logic
Physical Dimensions
5.1’’ x 4.0’’ x 1.4”
Inputs, Outputs & Controls
Power Light (PWR)
The power light is turned on when power is applied.
Trigger Input Terminals: T1 - T4, GD
Both dry contact closure and 3.3V/5V logic signal are acceptable. Trigger inputs may
work differently depending on the particular trigger mode described later. The GD termi-
nal is ground, connected internally to the power ground.
Reset Input Terminal: RS
Connect this input to the ground momentarily to reset the unit. Min. duration is 100 ms.
Busy Output Terminal: BY
This open collector output from an internal transistor can be controlled with more flex-
ibility if the unit runs in the Script mode. In all other modes it is automatically turned on
while playing audio, with a maximum sink current of 200 mA. It can be used to synchro-
nously activate an external relay for switching on a device such as a lamp or a motor.
Power Input Terminals: V+, GD
Use a well regulated DC power supply to obtain the best sound quality. Connect the power
supply’s positive output to terminal V+, and the negative output to terminal GD.
Line Output (LINE): 1/8” Stereo Phone Jack
This jack provides single ended line output.
Balance Knob (BAL)
This knob adjusts the output balance between the two channels. It should be set at the
middle (center detent) if the unit is configured for BTL (bridge tied load) mono out.
Volume Knob (VOL)
Turn this knob clockwise to increase the output volume. It affects both the speaker and
the line out.
Speaker Output Terminals: LF (left channel), GD, RT (right channel)
See the Speaker Connections section.
Relay Output Terminals (EM34A-R & EM34A-X only)
These terminals are on the back of the unit. Three terminals are provided for each
relay: NC (Normally Closed), NO (Normally Open) and Common. The contact is rated
at 12A/120VAC or 10A/24VDC.
Typical Wiring Diagram for Push Button Activation
