How to Connect your HAAS Machine with an I/O Connection

This guide explains how to connect a Haas CNC machine to MachineMetrics using a Sealevel digital I/O device when the machine does not support Haas Serial or Haas Next Gen Ethernet data collection.

Haas machines typically connect to MachineMetrics using one of two native methods:

• Haas Next Gen Control (Ethernet, Setting 143)

• Haas Serial (RS-232 + Moxa)

If neither connection method is supported—commonly due to machine age, missing ports, or unsupported firmware—then I/O is the correct integration method.

Using an I/O connection, MachineMetrics can collect:

• Part Count using one of the machine’s auxiliary relays

• Utilization using a current transducer (CT) monitoring spindle motor activity

Important Notice — Manufacturer Process

Haas wiring, relay configuration, and spindle drive layouts vary by model and year. This guide describes only the steps required to integrate MachineMetrics hardware. For machine-side wiring details, consult Haas support.

Feature Availability

How It Works

A. Part Count (Auxiliary Relay Output)

Haas machines include auxiliary relays that toggle via M-codes and provide dry contacts with terminals:

• COM (Common)

• NO (Normally Open)

• NC (Normally Closed)

MachineMetrics counts parts by detecting a short ON pulse from one of these relays.

Haas Auxiliary Relay Block

B. Utilization (Current Transducer)

A current transducer clamped around a single spindle motor output conductor produces a voltage proportional to motor load.
MachineMetrics interprets this signal as ACTIVE when spindle current is present and READY when idle.

Spindle Drive Location

Current Transducer Example

How to Add the Machine

A. Prerequisites

• MachineMetrics Edge Device

• Sealevel eI/O module (170 series recommended) 

• Current Transducer

• 24 VDC power supply or PoE (depending on Sealevel model)

• Access to the electrical cabinet

• Shielded low-voltage wiring (preferred for relay and CT signals)

• Ability to modify the part program end sequence

B. Hardware Installation

1. Provide Power to the Sealevel Device

Haas machines do not provide a 24 VDC accessory power output.
Supported options:

• External 120 VAC outlet

• Haas cabinet GFCI outlet

• 120 VAC → 24 VDC DIN-rail power supply

• PoE (for Sealevel 170POE models)

Example Power Arrangement

2. Wiring the Part Count Signal

Use any unused auxiliary relay.

Recommended (not required):

• COM → Sealevel Input Common

• NO → Sealevel OI1 (Opto Input 1)

Any OI channel may be used; update the script accordingly.

Add these commands at the end of the part program:

M51;
G04 P0.5;
M61;

Use shielded low-voltage wiring to reduce electrical noise.

Relay Pulse Example

3. Install the Current Transducer

1. Clamp the CT around one spindle motor output conductor.

2. Remove the CT range jumper if required for low-RPM sensitivity.

3. Wire the CT output to the Sealevel device:

Recommended (not required):

• CT + → AI0

• CT – → Analog Ground

Use shielded low-voltage wiring, routed away from VFD cables.

CT Installed on Conductor

C. Add Machine Flow Context

A Haas machine connected through I/O is added to MachineMetrics the same way as any other machine:

1. Go to Assets → Machines

2. Select Add Machines

3. Enter the machine name and assign the correct Edge Device

4. Add a Modbus data-collection method and configure it using the Sealevel device and adapter script

For full instructions on adding and managing machines, see Managing Machines in MachineMetrics.

D. Configure in MachineMetrics

1. Enter the Sealevel device’s IP address.

2. Assign the inputs:

Recommended (but not required):

• AI0 → Execution (CT)

• OI1 → Part Count (Relay)

4. Paste and adjust the following Sealevel Modbus adapter script:

version: 2
unit-id: 1
scan-interval: 0.1

registers:
  AI0:
    address: 0
    func: 4
    type: int16

coils:
  OI1:
    address: 1
    func: 2

variables:
  execution-raw:
    - source: AI0
    - resample: 0.1
    - min-delta: 0.1

  execution:
    - source: execution-raw > 50
    - off-delay: 25
    - state:
        - ACTIVE: this
        - READY: true

  part-count-raw:
    - source: OI1

  part-in:
    - source: OI1
    - falling-edge
    - count

data-items:
  - execution-raw
  - execution
  - part-count-raw
  - part-in

Verification & Testing

Part Count Test

Run in MDI:

M51;
G04 P0.5;
M61;

Confirm that the part count increments.

Utilization Test

Run the spindle at a low RPM.
The machine should show ACTIVE when current is detected.

CT/Execution Example Graph

Troubleshooting

Tips & Best Practices

• Use shielded low-voltage wiring for CT and relay signals.

• Keep CT wiring separated from motor and VFD cabling.

• Document which AI/OI channels are used.

• Ensure CT type matches the spindle motor (AC vs DC).

• Use the Haas relay for part counting whenever possible; proximity sensors should only be used if no relay output exists.

Related Articles

• How to Connect to HAAS Next Gen Control (Machine Data Collection)

• How to Collect data using HAAS Serial

• Sealevel 170POE Overview

• How to Install a Current Transducer

• Installing a Part-Count Proximity Sensor with Sealevel 170POE-ROHS