Automated Test & Measurement Modules
RS485 Automated Test & Measurement Modules
The RS485 Automated Test & Measurement Modules are designed for test engineers working on FCT, ICT, automated test equipment and industrial automation projects that require multi-channel measurement, signal switching, fixture control and current measurement. The series includes the M416 16CH MUX Module, S424 24CH Switch Module and A404 4CH Current MUX Module. They support modular expansion through RS485 communication and provide a communication protocol, LabVIEW driver and example VIs, helping engineers understand the products, compare models, judge use cases and contact onTAP for integration support.
Platform Overview
- A modular signal switching and measurement product series for automated test and measurement systems
- Uses RS485 communication for multi-module expansion and distributed control
- M416 is used for multi-channel voltage, resistance and electrical parameter measurement, supporting two-wire and four-wire measurement architectures
- S424 is used for small-signal switching, test resource switching and automation equipment control, with 4 isolated digital inputs
- A404 is used for multi-channel current measurement and simplifies test system design through a dedicated current measurement switching structure
- Provides communication protocol, LabVIEW driver and example VIs for integration with FCT and automated test systems
Core Models
M416 — 16CH MUX MODULE
Used for multi-channel voltage, resistance and other electrical parameter measurement in automated test and measurement systems.
The typical architecture connects a DMM to the M416, and the M416 switches to 16 DUT measurement channels. The application is similar to the multi-channel measurement architecture of Keysight 34970/34901-type systems, while RS485 provides more flexible modular expansion. Two-wire and four-wire measurement are supported.
DMM ↓ M416 ↓ 16 DUT measurement channels
Technical Parameters
| Model | M416 |
|---|---|
| Dimensions | 110 × 110 mm |
| Mounting | 4 mounting holes, 4 mm hole diameter |
| Communication | RS485, MAX485 transceiver chip |
| Channels | 16 channels per board |
| Address | 4-bit address lines |
| Maximum Expansion | 16 groups |
| Maximum Measurement Channels | 16 × 16 = 256 channels |
| Power Supply | 9~30VDC |
| Relay | Omron G5V-2-H-5V |
| Connector | 5.08 mm pitch |
| Software | Communication protocol, LabVIEW driver and example VIs provided |
Typical Applications
S424 — 24CH SWITCH MODULE
Used for small-signal switching, test resource switching and automation equipment control in automated test systems.
In addition to 24 relay channels, S424 integrates 4 isolated digital inputs. The digital inputs can be used for light curtains, buttons, sensors, position detection and automated test fixture status detection. Its positioning can be compared with Keysight 34970/34903-type switch applications, while S424 additionally integrates 4 isolated digital inputs.
Technical Parameters
| Model | S424 |
|---|---|
| Dimensions | 110 × 149 mm |
| Mounting | 4 mounting holes, 4 mm hole diameter |
| Communication | RS485, MAX485 transceiver chip |
| Relay Channels | 24 channels |
| Digital Inputs | 4 isolated digital inputs, wide voltage range supported |
| Address | 4-bit address |
| Maximum Expansion | 16 groups |
| Maximum Relays | 24 × 16 = 384 channels |
| Maximum Digital Inputs | 4 × 16 = 64 channels |
| Power Supply | 9~30VDC |
| Relay | Panasonic APAN3105 |
| Connector | 5.08 mm pitch |
| Software | Communication protocol, LabVIEW driver and example VIs |
| Supports | Single relay control, relay group control and digital input status reading |
Typical Applications
A404 — 4CH CURRENT MUX MODULE
Used for multi-channel current measurement in automated test systems.
Current measurement requires the ammeter to be connected in series with the circuit under test. If a general relay board is used for multi-channel current measurement, the system wiring becomes very complex. A404 uses a dedicated current measurement switching structure to simplify multi-channel current test system design.
Note: Multi-channel current measurement requires additional switches configured according to the actual test circuit and cannot be simply connected in parallel.
Technical Parameters
| Model | A404 |
|---|---|
| Dimensions | 110 × 63 mm |
| Mounting | 4 mounting holes, 4 mm hole diameter |
| Communication | RS485, MAX485 transceiver chip |
| Channels | 4 channels |
| Address | 4-bit address |
| Maximum Expansion | 16 groups |
| Maximum Current Measurement Channel Architecture | Up to 64 current measurement channel architecture |
| Power Supply | 9~30VDC |
| Relay | Omron G5V-2-H-5V |
| Connector | 5.08 mm pitch |
| Software | Communication protocol, LabVIEW driver and example VIs |
| Customization | 8-channel, 16-channel and 32-channel |
Typical Applications
Quick Selection
| Requirement | Recommended Model |
|---|---|
| Multi-channel voltage measurement | M416 |
| Multi-channel resistance measurement | M416 |
| Two-wire/Four-wire measurement | M416 |
| Multi-channel signal switching | S424 |
| Automated test fixture control | S424 |
| Light curtain/Button/Sensor input | S424 |
| Multi-channel current measurement | A404 |
| DUT operating current test | A404 |
| Complete FCT test system | M416 + S424 + A404 |
System Architecture
The three modules can be used together to form a modular automated test and measurement platform. PC test software connects to M416, S424 and A404 through the RS485 bus, covering voltage/resistance measurement, signal/control switching and current measurement, and finally connecting to the DUT.
Software and Open Protocol
The module series provides an open communication protocol, LabVIEW driver and example VIs, suitable for integration with existing FCT software, automated test platforms or host applications. This marketing page only shows a simplified protocol frame, not the complete low-level protocol.
Supported Capabilities
- Module address
- Channel control
- Status reading
- Model identification
- S424 group control
- S424 digital input reading
Provided Resources
- Communication protocol
- LabVIEW driver
- Example VIs
Need help selecting RS485 automated test modules?
onTAP can support module selection, LabVIEW driver integration, protocol integration and FCT automated test system integration based on DUT interfaces, measurement items, test resources, fixture structure and host software requirements.
Contact onTAP