MTL 8121-DI-DC-01 Discrete Input Module

Overview

The MTL 8121-DI-DC-01 is a 16-channel discrete input module for the PAC8000 I/O system. It supports dry contact switches and pulse counting for flexible digital input applications. Engineers use it in compact, high-density installations that demand reliable performance. Additionally, the module operates using the system’s bussed field power, ensuring efficiency.

Technical Specifications

• Manufacturer: MTL Instruments (Emerson)

• Model Number: 8121-DI-DC-01

• Product Type: Discrete Input Module

• Number of Channels: 16

• Input Type: Dry contact switches (source type)

• Input Voltage Range: 18–30 VDC

• ON Current Threshold: >1.2 mA

• OFF Current Threshold: <0.3 mA

• Wetting Current: 2.8 mA typical

• Minimum Pulse Width: 5 ms

• Max Frequency (Pulse Mode): 100 Hz (no debounce)

• Isolation: 250 V AC channel to Railbus; no channel-to-channel isolation

• Selectable Input Filter: Fast, slow, or user defined

• Latch Inputs: Enable or disable

• Latch Polarity: Latch on high or latch on low

• Pulse Counting: Enable or disable

• Response Time: ≤ 5 ms from field event to Railbus

• FM Non-incendive Field Wiring Parameters: Voc = 30 V; Isc = 3.5 mA; Ca = 0.12 μF; La = 1000 mH

• Railbus (12V) Current: 90 mA typical, 135 mA maximum

• Bussed Field Power: 60 mA at 18–30 VDC

• Module Key Code: E1

• Module Width: 42 mm

• Weight: 210 g