IS420YDIAS1B Contact Input Module

The Mark* VIeS Functional Safety Contact Input module provides an interface between
discrete contact process sensors (24 discrete inputs) and Mark VIeS Safety control logic.
The Contact Input module consists of two orderable parts: the contact input I/Opack and
the contact input terminal board. All safety contact input modules use the same I/Opack,
IS420YDIAS1B. Multiple DIN-rail mounted terminal boards are available to provide the
necessary contact voltages, redundancy, and terminal block styles.
The Contact Input module is available in both Simplex and Triple Modular Redundant
(TMR) configurations. Users can select the configuration that best addresses their needs
for availability and SIL level. This document discusses the Simplex Contact Input (STCI)
terminal board and the Contact Input (TBCI) terminal board. The TBCI terminal board
offers TMR capability but it can also be used in a Simplex configuration with a single
YDIA I/Opack. In a TMR I/Oconfiguration, the controller performs 2-out-of-3 voting on
the discrete inputs. In a Dual I/Oconfiguration, the controllers listen to the first reporting
YDIA I/Opack (no voting).

IS420YDIAS1B

The STCI terminal board is a compact contactinputterminal board
used for Simplex configurations. The STCI accepts 24 contact
inputs that are supplied with a nominal 24 or 48 V dc excitation
from an external source, or I/O wetting power supply. The contact
inputs have noise suppression to protect against surge and highfrequency noise. The YDIA mounts directly on the STCI terminal
board. The STCI is available in multiple versions to meet customer
requirements. The STCI Terminal Board with YDIA I/OPack
Specifications table provides the specifications for the STCI versions
available for use in the Mark VIeS Functional Safety System.