Ametek / VTI Instruments / VXI Technology VM1548 48-Channel TTL I/O Module

The Ametek/VTI Instruments/VXI Technology VM1548 is a 48-channel TTL I/O module for VXI bus systems, delivering high-density digital I/O in a single C-size card slot. Part of the VMIP™ family, it organizes channels into six independently configurable 8-bit groups, each selectable as input or output under program control. The module supports single or double buffering for real-time or synchronized data access, with data throughput reaching approximately 500 ns via register-based access.

It integrates trigger and clock distribution across all channels, enabling precise synchronization of UUT handshaking and multi-channel data collection.

Technical Specifications

• Channel Architecture: 48 channels organized as six 8-bit groups; each group independently configurable as input or output


• Buffering Options: Single-buffered for real-time access; double-buffered for synchronized input/output operations


• Logic Levels: TTL compatible (standard VM1548); VM1548C variant supports TTL or up to 60 V, 300 mA open-collector outputs


• Data Throughput: Register-based access delivers approximately 500 ns per operation (controller and software dependent)


• Data Format Support: ASCII, Hex, Octal, and Binary output

Key Features

• Dual Data Access Methods: Word serial message-based interface for programmatic clarity; register-based access for maximum throughput


• Flexible Clock Sources: Front panel inputs (one per 8-bit group), VXIbus TTL trigger bus, or word serial command


• Event-Triggered Backplane Signaling: Monitors clock inputs to detect events and transmit triggers to the VXIbus backplane for device handshaking


• Multi-Module Stacking: Achieves up to 144 I/O channels by combining multiple VM1548 modules via a VM9000 carrier in a single slot


• VXIplug&play Drivers: Supplied drivers and SCPI compliance simplify integration and control

Typical Applications Automated test systems requiring synchronized multi-channel digital control, UUT stimulus/response monitoring, and cross-module triggering in compact VXI chassis.

Compatibility & Integration C-size VXIbus form factor; VMIP™ family member; requires VM9000 carrier (holds up to three VMIP™ instruments per slot); VXIplug&play drivers and SCPI compliant.