NI FP-CTR-502 8-Channel Counter Input Module

The NI FP-CTR-502 is an 8-channel counter input module for the FieldPoint system, delivering high-speed event counting and timing measurement in industrial environments. With cascadable 16-bit registers expandable to 128 bits and a maximum input frequency of 50 kHz, the module excels at frequency measurement, quadrature encoder tracking, and general event counting across eight independent channels. Four configurable gate inputs enable flexible counting control, while four programmable outputs support both generic digital signaling and dedicated count-channel associations.

– Technical Specifications

• Counter Resolution: 16-bit registers, cascadable to 128 bits
• Input Channels: 8 count inputs; 4 gate inputs (configurable as gates or digital inputs)
• Output Channels: 4 configurable outputs (generic digital or count-channel associated)
• Maximum Input Frequency: 50 kHz
• Configurable Low-Pass Filter: 50 kHz or 200 Hz on count-input channels
• Input Signal Range: 5 to 30 VDC (sourcing inputs)
• Internal Frequency References: 1 kHz and 32 kHz
• Power Supply Range: 5 to 30 VDC field device input
• Maximum Terminal Current: 2 A per terminal (requires 2 A fast-acting fuse)
• VOUT Load Fuse: 1 A maximum, fast-acting
• Overvoltage Protection: 2,300 Vrms transient
• Isolation: Optical bank isolation between I/O and communication bus
• Terminal Count Default: 65,535 (user-programmable with rollover or reset options)

– Key Features

• TTL and multi-voltage (5, 12, 24 VDC) instrument compatibility
• Sinking output configuration
• Gate-controlled counting: Always Disabled, Always Enabled (default), or gate-input association
• Gate inputs exclude low-pass filtering
• Counter cascading for extended resolution applications

– Typical Applications

• Frequency and period measurement
• Encoder position tracking and velocity calculation
• General industrial event counting
• Gated pulse accumulation and timing analysis

– Compatibility & Integration

The FP-CTR-502 integrates directly into NI FieldPoint systems with optical isolation between I/O channels and the communication bus, protecting against transient overvoltages in harsh industrial settings.