The Traditional I/O subsystem includes:

I/O interface carrier (a DIN rail surface mounted) on which all I/O related components are installed.

Bulk AC to 24V DC power supply for field devices.

An I/O interface consisting of an I/O card and an I/O terminal block.

A variety of analog and discrete I/O cards enclosed  in a common form factor that easily plugs into the  I/O interface carrier.

A variety of I/O terminal blocks mounted on the I/O interface carrier that can be pre-wired before I/O card installation.

I/O Cards

A variety of analog and discrete I/O cards are available to meet your specific requirements.

The following cards support simplex or redundant installation:

AI 4-20 mA HART 8 channels

AO-4-20 mA HART 8 channels

DI, 24V DC Dry Contact, 8 channels

DO 24V DC High-Side, 8 channels

AI (Plus) 4-20 mA HART, 16 channels

AO (Plus) 4-20 mA HART, 16 channels

DI (Plus) 24V DC, Dry Contact, 32 channels

DO (Plus) 24V DC, High-Side, 32 channels

The following I/O cards are supported in simplex format  to meet your field wiring needs.

AI Isolated, 4 channels

RTD, 8-channels

Thermocouple, 8 channels

Millivolt, 8 channels

DI, High Density, 32 channels

DI 24V DC Isolated, 8 channels

Multi-Function, 4 channels (Isolated DI)

Sequence of Event, 16 channels (DI 24 V DC)

DI 120V AC Low Side Detection, 8 channels

DI 120V AC Isolated, 8 channels

DO 24V DC Isolated, 8 channels

DO 120/230V AC High-Side, 8 channels

DO 120/230 Isolated, 8 channels

All I/O cards are enclosed in a common form factor that plugs into the I/O interface carrier. The housing is clearly labeled with the enclosed I/O card type. All cards have power and internal error indicators. Eight-channel cards have clearly visible channel

status LEDs.

All cards meet ISA G3 corrosion specifications by the careful selection of superior electronic components and the use of conformal coating.

Pulse Counters are available on most DI cards. The supported maximum frequency varies from 0.1 Hz on AC signals to  75 or 120 Hz on 24V DC inputs. For higher pulse counts,  up to 50 KHz, use the Multi-Function card’s high speed pulse input.

The DeltaV system provides control module level time stamping for log events and alarms. For greater event resolution, the 16-channel Sequence-of-Events DI card can provide signal driven events to a resolution of +/- 0.25 ms per card, or within 1 ms per controller. Please refer to the Sequence-of-Events PDS for more information on Sequence-of-Event data collection and system options for this feature.

I/O Card Redundancy

Redundant I/O cards are available for critical applications.

The same card can be used in simplex or redundant applications. When installed on a two-wide redundant terminal block, the cards are recognized as a redundant pair by the controller. The controller scans each card and determines which card is acting as the active interface. When a fault is detected, the system automatically switches to the standby I/O card.

DeltaV Control modules reference simplex and redundant I/O channels identically and there is no special configuration required to take advantage of redundancy.

Switchover of a redundant I/O card is completed within two scans of the I/O bus. Make-before-break contacts ensure digital field instruments remain powered and the process is undisturbed. Analog output signals are briefly driven by both cards for < 5 ms during switchover of the card.

Hardware Alerts automatically report hardware integrity errors for both the primary and secondary cards. Any event that causes a switchover is also reported automatically through the system hardware alerts and is logged in the Event Chronicle.

Events that can cause a switchover include.

Hardware failure within the active card.

Communications failure between the active card and the controller.

Detection of a fault in the field wiring.

A switchover may also be initiated from the diagnostics explorer, and the health and status of both cards and  their channels are available in the diagnostics explorer.

The system automatically commissions a new standby card.

In safe areas, failed cards can be replaced under power.

In hazardous areas, appropriate installation procedures must be followed.