A06B-6079-H101 FANUC-A06B-6079-H101-Servo-Amplifier-Module A06B6079H101

Fanuc A06B-6079-H101 | Alpha Servo Amplifier Module — SVM1-12, Single-Axis, 283–325V / 0.75kW, 3.0A Output, Type A/B PWM Interface

Overview

The Fanuc A06B-6079-H101 is the SVM1-12 — the entry-level single-axis module in Fanuc's alpha servo amplifier series, rated at 3.0A continuous output on its L-axis channel from a 0.75kW DC bus input. It is the smallest drive in the A06B-6079 single-axis SVM1 family, matched to the lightest motors in Fanuc's alpha motor lineup.

Where the larger SVM1 variants handle progressively heavier axes with greater power demand, the SVM1-12 is specified for compact axes running α1/3000 and α2/3000 motors — CNC machining centre table and saddle drives, wire EDM electrode positioning axes, small robotic joint drives, and any axis where the motor's continuous current demand falls comfortably within 3.0A.

The 60mm module width — the narrowest format in the alpha SVM series — is a direct consequence of the SVM1-12's modest output class.

The IPM (Intelligent Power Module) devices that form the output stage at 3.0A need only be 20A-class devices, which fit within a 60mm panel width alongside the wiring board and control card.

This narrow format is a practical cabinet design asset: in a machine with multiple individual single-axis drives, the SVM1-12's 60mm width allows fitting more axis drives within a given rail length compared to wider SVM modules.

As with all A06B-6079 series modules, the SVM1-12 draws its operating power from the alpha PSM's shared DC bus and communicates with the CNC through the PWM serial feedback interface.

Type A and Type B interface compatibility makes the H101 serviceable across a broad range of CNC control generations without modification, provided the replacement module's interface is set to match the machine's existing CNC control type.

One important installation detail: the module may be configured with either one or two CX5 battery ports for absolute encoder backup, and the replacement must match the original configuration.

Key Specifications

SVM1-12 in the Alpha Drive System

Within the alpha amplifier module system, the SVM1-12 occupies one of the smallest physical footprints while delivering complete single-axis servo control.

The module receives position and velocity commands from the CNC's axis control processor via the PWM serial link, closes the current loop internally using the IPM's built-in current regulation, and processes the motor's encoder feedback through the CNC's position loop at each servo cycle period.

Physically, the module mounts on the alpha amplifier rail between the PSM and adjacent SVM or SPM modules, with the DC bus connector at the rear and the motor power output terminals at the bottom.

The CNC's servo interface cable connects to the wiring board's JN series connectors at the top, carrying the PWM command and feedback signals. The motor power cable (three-phase U/V/W) and the motor's feedback cable (encoder) connect separately.

The 0.75kW DC bus demand of the SVM1-12 is the smallest contribution to the PSM's total load in a multi-module installation.

In a machine with an SVM1-12 driving each of three axes and a 5.5kW spindle module, the total bus demand is approximately 7.75kW — well within the PSM-11's 13.8kW capacity and even within the smaller PSM-5.5's 6.8kW capacity for a two-servo-axis machine without the spindle.

α1/3000 and α2/3000 — Light-Duty Precision Axis Drives

The alpha series motors matched to the SVM1-12 are compact, high-speed motors designed for axes where dynamic response — the ability to accelerate and decelerate quickly with minimal overshoot — is more critical than raw continuous torque.

The α1/3000 produces its rated torque across a speed range up to 3000rpm, with a low moment of inertia that makes it highly responsive to velocity command changes.

These characteristics make it ideal for fast-cycling CNC axes on small machining centres and EDM machines where each axis reversal during contouring must follow the programmed path without lag or oscillation.

The α2/3000 provides slightly higher continuous torque at the same rated speed, covering axes with heavier carriage or table masses while remaining within the SVM1-12's 3.0A continuous current rating.

FAQ

Q1: How is the CX5 battery port count determined before ordering?

Inspect the existing module before removal: count the CX5 connectors physically visible on the module's wiring board.

A module with one CX5 serves one absolute encoder axis; two CX5 ports serve two absolute encoder axes from the same module. 

Some machine configurations route two axes' encoder batteries through a single SVM1-12. If the incorrect port count is installed, one or more axes will lose absolute position on power-off and require reference return before machining can resume.

Q2: What is the FSSB equivalent of the A06B-6079-H101?

The FSSB optical fibre interface equivalent of the SVM1-12 is the A06B-6096-H101. Both are SVM1-12 modules with identical 3.0A, 0.75kW ratings. The difference is communication protocol: the H101 (A06B-6079 series) uses PWM serial feedback; the A06B-6096-H101 uses FSSB fibre optic.

They cannot be substituted directly — the machine's CNC type determines which interface is required.

Q3: Why is this drive described as Type A/B compatible when other SVM modules are Type A-only or Type B-only?

The 60mm-class alpha modules (SVM1-12 and SVM1-20) were designed with interface flexibility from early in the product line, accommodating both Type A and Type B CNC interface protocols through a hardware selection on the module.

Larger SVM modules in the A06B-6079 series were often released in Type A-only configurations within the H101–H108 numbering, with separate Type B variants in the A06B-6080 series.

The SVM1-12's dual compatibility simplifies spare parts inventory for service providers supporting machines across different CNC control generations.

Q4: Can the A06B-6079-H101 be operated with no load (no motor connected) for testing?

Operating the SVM1-12 without a motor connected is not a standard commissioning or testing procedure. The CNC typically detects the absence of motor feedback and generates a servo alarm before enabling the drive.

Qualified repair facilities use dedicated load test hardware — resistive loads or actual motor loads on controlled test rigs — to verify drive output stage function.

Field testing without a motor, even briefly, is not recommended because some drive protection functions only operate correctly with a motor present in the output circuit.

Q5: What alarm code combination best distinguishes a module fault from a motor fault on the A06B-6079-H101?

The standard diagnostic sequence is: power off, disconnect the motor's U/V/W power cables from the module's output terminals. With cables disconnected, power on and release the emergency stop.

If the overcurrent alarm (typically corresponding to Alarm 8/9/A on the module LED) clears, the fault is in the motor or motor cable — test motor insulation to protective earth (acceptable values are several hundred megaohms or more).

If the alarm persists with motor cables removed, the fault is in the drive output stage, and the module requires repair or exchange.

This sequence prevents incorrectly replacing a healthy drive when the root cause is a deteriorating motor.