The Yokogawa VL100-DR1A-08 is a 16-channel Digital Input (DI) Module designed for the Yokogawa ProSafe-RS Safety Instrumented System (SIS) or the CENTUM VP Distributed Control System (DCS).<br />
This module is a critical component for reading the state of field devices such as emergency stop buttons, pressure switches, flow switches, or any other critical safety or process-related contact. It is typically installed in a ruggedized industrial rack or node (like the N-IO node) to provide high-density digital signal acquisition in harsh plant environments. The "08" in the model number is a common Yokogawa suffix indicating a digital input function.
| Function | 16-channel Isolated Digital Input (Contact Input) |
| Input Signal Type | Dry Contact (volt-free contact). The module provides a wetting voltage. |
| Input Voltage | 24 V DC (sourced by the module itself) |
| Number of Channels | 16 |
| On/Off Voltage Level | ON (Close): ≤ 5 V DC
OFF (Open): ≥ 15 V DC |
| Input Impedance | Approximately 5.6 kΩ |
| Isolation | Channel-to-Channel Isolation: Yes
Channel-to-Backplane Isolation: Yes |
| Response Time | OFF → ON: Typically 5 ms max.
ON → OFF: Typically 5 ms max. (Configurable via software for noise immunity) |
| Internal Power Consumption | Typically 120 mA @ 5 V (from backplane) |
| Field-Side Power | The module supplies a shared 24V DC sourcing voltage for all input points. The current draw per point depends on the field loop. |
| Connection Method | The module has a removable front connector (often a Hirose-type connector) that interfaces with a terminal block unit (TBU), which is wired to the field devices. |
| Compatible Systems | • Yokogawa ProSafe-RS (Safety Instrumented System)
• Yokogawa CENTUM VP (Distributed Control System) |
| Mounting | Installed in a dedicated N-IO Node or other compatible Yokogawa rack assemblies. |
| Diagnostics | Built-in diagnostics for module health, communication errors, and field power supply monitoring. |
| Status Indicators | Per Channel: LED indicates the ON/OFF state of the input.
Module-Wide: LEDs for module status (RUN, ERR, etc.) and power. |