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ACU2 (v2)

Latest Firmware Version: 3.9

Technical User Guide

The following information is from the ACU2 (v2) Technical User Guide. For a comprehensive overview of the ACU2 (v2), go to the full guide:

View Guide

Version 2 of the ACE Communication Unit – 2nd Generation, also known as the ACU2 (v2), is a compact, 48 kHz digital and audio distribution module that connects remotely located operator stations and live radios to the ACENet network. It provides low noise, analog-to-digital conversion, and low-latency audio distribution.

A comprehensive overview of the ACU2 (v2) can be found in the Technical User Guide.

General Specifications

Compatible with Telestra
Part Number ACU2-04
Dimensions 7.9" length (depth) x 7.489" width x 1.724" height
Weight A packaged ACU2 (v2) weighs 2 lbs. The included power supply weighs 0.5 lbs.
Power Source Individual power supply, included.
Power Consumption +15 VDC, 2 A
Mean Time Between Failure (MTBF) 1,405,667 hours (COTS)
309,154 hours (military)

Audio Input/Output

Audio Input

Impedance 830 Ω single-ended (1.6K Ω differential)
Max Input Level 6.5 Vpp
Gain -8 dB, +2 dB to +57 dB; default value of 40 dB; software configurable*
Microphone Power +12 VDC; off by default; software-enabled
Frequency Response 20 Hz to 20 kHz, +/- 1.5 dB

* The ACU2 (v2) gain covers a total range of 65 dB. Between +2 dB and +57 dB, the gain can be set in 1 dB steps. A value of -8 dB is available for input signals greater than line level. The range -8 dB to +2 dB cannot be selected as a function of design.

Audio Output

Impedance 10 Ω
Current 0.15 A
Gain -25 dB to +10 dB; default value of 10 dB
Level 2.2 Vpp (1.68 VAC RMS) into 8 Ω
Power 0.08 W at 8 Ω
Frequency Response 20 Hz to 20 kHz
Max Output Signal 5 Vpp

Memory Devices

Volatile Memory

Type Size User Modifiable Function Process to Clear
MCU Internal 512 KB No Used as RAM for an internal MCU Remove power
Count to 30
Restore power

Nonvolatile Memory

Type Size User Modifiable Function Process to Clear
MCU Internal 2 MB Yes Firmware None
EEPROM 32 KB Yes Device-specific settings None


RJ-12 Pinout for RS-422

(Serial Connection)

RJ-12 Pinout for RS-232

(Serial Connection)

DB-15 Connector

(Audio Interface)


ASTi warrants to the buyer and its customers that all items delivered and all services rendered hereunder will conform to the requirements hereof and will be free from defects. In addition to other remedies that may be available at law or in equity, the buyer may return to ASTi any nonconforming or defective items or require correction or replacement of the item, all at ASTi’s risk and expense. If the buyer does not require correction or replacement of nonconforming or defective items, ASTi shall repay such portion of the contract price or such additional amount as is equitable under the circumstances.

Warranty period: 12 months from shipment date