Emerson DeltaV  ™   S-series Traditional I/O

In the field of process industry automation, the reliability, flexibility, and ease of maintenance of I/O systems are directly related to the return on investment and operational efficiency of the entire control system. Emerson's DeltaV ™ The S series traditional I/O modules in distributed control systems (DCS) have become an ideal choice for process control applications due to their modular design, robust and durable environmental adaptability, and plug and play convenience. This article is based on DeltaV ™  A comprehensive interpretation of the technical characteristics, hardware specifications, redundancy mechanisms, and system integration of the S series traditional I/O product data sheet.

Product Overview and Core Advantages

DeltaV ™  On the basis of inheriting the mature characteristics of M-series I/O, the S series traditional I/O modules further enhance installation convenience and environmental adaptability. This subsystem is designed specifically for harsh on-site environments, supports online expansion, and aims to maximize the protection of user investments. Its core advantages are reflected in the following five aspects:

Modular and flexible construction: Each controller can support up to eight I/O carriers, forming a powerful passive bus that provides communication and power for up to 64 I/O interfaces. Each interface is equipped with a corresponding I/O terminal block, which can be installed in any I/O slot on the bus. Both carrier and interface support online addition without interrupting existing I/O communication. This design allows users to purchase I/O cards on demand and flexibly expand as the system grows.

Shorten installation time and cost: The S series I/O interface is designed for fast assembly and error free maintenance. All carriers are installed on T-DIN rails using a snap fit, and the interface can be directly inserted into the I/O slot without the need for any tools. The independent terminal block ensures that the insertion and removal of I/O cards does not affect on-site wiring at all. Some cards support fuse terminal blocks, and their built-in online fuses can be pulled out to isolate the on-site circuit power supply. The unique I/O function key mechanism ensures that only the correct card can be inserted into the corresponding terminal block, fundamentally eliminating the risk of incorrect installation.

Convenient online expansion capability: The S series I/O carriers and interfaces can be easily added online without affecting existing I/O communication. The new carrier can be directly connected to the right side of the existing carrier or installed on different DIN rails through extension cables. The controller automatically detects new hardware and senses it in the configuration database, greatly simplifying the system expansion process.

On site installation capability: All S series traditional I/O interfaces support an extreme operating temperature range of -40 to 70 ℃ and can be directly installed in the on-site junction box. This can not only significantly reduce the equipment footprint and free up valuable control room space, but also save a lot of wiring costs by eliminating long-distance multi-core cable wiring. The integrated design of the I/O subsystem can even eliminate intermediate terminal cabinets, further reducing the total capital cost.

1: 1. Redundancy and Plug and Play: For critical field circuits, the S series offers four types of I/O cards that support redundant terminal blocks. Simply install a pair of cards on the designated redundant terminal block, and DeltaV DCS will automatically recognize them as redundant pairs without the need for additional configuration. All components are plug and play type, automatically sensed by the controller, without any addressing switches or jumpers.

System composition and hardware architecture

The S series traditional I/O subsystem consists of the following core components:

I/O interface carrier: Installed on a DIN rail, it provides physical support, power bus, and communication backplane for all I/O components. The carrier integrates bus based on-site power distribution, divided into primary and secondary power supplies for odd and even slots, and each slot is equipped with an independent fuse to protect other cards from faults.

I/O interface: composed of I/O cards and matching I/O terminal blocks. The card adopts a unified external packaging, clearly identifies the type, and is equipped with LED indicators for power supply, internal errors, and channel status. All cards are coated with three proof paint, meeting the ISA G3 corrosive gas standard.

I/O terminal block: Provides on-site signal wiring interfaces and supports multiple types (such as standard, fuse, redundant, and large-scale wiring) to meet different functional and environmental requirements. Its unique rotation locking key mechanism ensures a unique match with the corresponding I/O card.

Detailed Explanation of I/O Card Technical Specifications

DeltaV ™  The S series provides a wide range of I/O cards, covering various signal types such as analog and discrete, to meet diverse process control requirements. All cards support wide temperature operation and have high precision and isolation characteristics.

3.1 Analog input card

8-channel 4-20mA HART input card: supports 2/4-wire transmitters, with an accuracy of 0.1% and a resolution of 16 bits. Each channel is optically isolated and tested for a withstand voltage of 1500V DC. Supports transparent transmission of HART protocol, facilitating intelligent device management through AMS Device Manager. Optional 2.0A fuse.

16 channel 4-20mA HART input card (including Plus type): Provides higher channel density with an accuracy of 0.2%. The Plus card supports redundant configuration and can be used in conjunction with 48 pin large-scale terminal blocks.

8-channel RTD input card: supports 2/3/4 wire RTD (Pt100, Pt200, Pt500, Ni120, Cu10) and resistance measurement. Excitation current of 100 μ A, 16 bit resolution. User defined RTDs can be linearized with high precision using the Callendar Van Dusen equation.

8-channel thermocouple/mV input card: supports B, E, J, K, N, R, S, T-type thermocouples and millivolt signals. Channel grouping isolation, built-in cold junction compensation (CJC), extremely low open circuit detection current.

4-channel isolated input card: highly versatile, can be independently configured as multiple input types such as thermocouple, RTD, mV, V, etc. Both inter channel and inter channel systems achieve high voltage isolation up to 600V AC, suitable for complex situations with high common mode voltage or potential fluctuations.

3.2 Analog output card

8-channel 4-20mA HART output card: accuracy 0.25% (-40 to 60 ℃), resolution 14 bits, output load capacity up to 700 Ω @ 20mA. Supports HART transparent transmission, with optional fuses and redundant configurations.

16 channel 4-20mA HART output card (Plus type): high-density design, supports redundant configuration, suitable for large-scale analog output requirements.

3.3 Discrete input card

8/32 channel 24V DC dry contact input card: detects levels ON>2.2mA (8ch)/2mA (32ch), OFF<1mA (8ch)/0.25mA (32ch). Supports pulse counting function (up to 75Hz). When used in conjunction with large-scale terminal blocks, the 32 channel Plus card supports wire breakage detection function.

8-channel 24V DC isolated input card: The channels are isolated from each other, with a detection level of ON>10V and OFF<5V, and strong anti-interference ability.

4-channel pulse counting input card: supports input frequencies up to 50kHz, minimum pulse width of 10 μ s, 32-bit counter, suitable for high-speed counting or flow integration applications.

16 channel sequence of events (SOE) card: With a resolution of up to ± 0.25ms (inside the card), it is used to accurately record the sequence and time of switch events, and is a key tool for fault recall.

8-channel 120V AC input card: provides two types of dry contacts and isolation to meet the requirements of AC signal detection.

3.4 Discrete output card

8-channel 24V DC output card: provides two options: high side drive and isolated type. Each channel has a rated current of 1A and supports multiple output modes: discrete output, instantaneous output, and continuous pulse output (with a period of 100ms to 100s and a resolution of 5ms).

32 channel 24V DC high side output card (Plus type): 100mA per channel, total current 3.2A@24V When used in conjunction with large-scale terminal blocks, DC Plus cards support wire breakage detection function.

8-channel 120/230V AC output card: provides high side drive and isolation type, with 1A per channel, suitable for AC load control.

Redundancy and high availability

The redundant design of S series I/O aims to maximize system availability. Key components (such as specific models of AI, AO, DI, DO) can be installed on dedicated dual width redundant terminal blocks. The controller automatically scans and determines the main card. When a hardware failure, communication interruption, or field line failure is detected on the main card, the system automatically and undisturbed switches to the backup card within a maximum of two I/O bus scanning cycles. During the switching period, the analog output is driven by dual cards simultaneously for<5ms, ensuring no disturbance to the on-site actuator. The hardware alarm will automatically report the health status and switching events of the primary and backup cards, making it easier for operation and maintenance personnel to timely grasp the system status.

System compatibility and certification

The S series traditional I/O needs to be used in conjunction with SQ or SX series controllers and S series horizontal carriers. Starting from DeltaV v11.3.1, S-series and M-series controllers can coexist in the same control network. The Plus series cards require DeltaV software version v13.3 or higher. The S series I/O does not support vertical carrier, and vertical installation applications require electronic wiring technology with CHARMS I/O.

The product has passed CE, FM, CSA, ATEX, IECEx and multiple classification society certifications, and can be safely used in hazardous areas such as Class I Division 2 and Zone 2. All cards comply with ISA G3 corrosive gas standards.