Yokogawa STB Series Modules: STB4D-00 S2 Pressure Clamp Terminal Block

Technical Dossier

Product Details And Specifications

Yokogawa STB Series Technical Notes

The Evolution of STB Series Architecture

The STB series was introduced alongside Yokogawa's CENTUM CS platform in the mid-1990s as a modular, DIN-rail-mountable termination solution. Early variants — including the STB4 and STB8 families — used screw-type terminals and were designed for direct field cable termination without marshalling panels. As CENTUM CS 3000 succeeded the original CS platform in the early 2000s, Yokogawa refined the STB range to introduce pressure clamp (spring-clamp) termination variants, designated by the suffix convention used in models such as the STB4D-00 S2. The pressure clamp mechanism eliminates the torque-dependency of screw terminals, reducing installation error and vibration-induced loosening in high-cycle industrial environments.

With the transition to CENTUM VP (circa 2008 onward), the STB series maintained backward mechanical compatibility with CS 3000 I/O modules, allowing brownfield upgrades without full field wiring replacement. However, certain early STB variants are now classified as mature or end-of-active-production by Yokogawa, meaning procurement relies on authorized aftermarket distributors and certified refurbishers. The STB4D-00 S2 specifically is a 4-channel pressure clamp terminal block, compatible with analog input modules in the CENTUM CS 3000 and CENTUM VP ecosystems.

STB Series Full Catalog & Functionalities (SKU List)

The following represents a structured reference index of the Yokogawa STB series, organized by terminal type and channel count. All models listed are verified members of the STB product family.

Analog Input Terminal Blocks (Pressure Clamp / Screw Type)

• STB4D-00 S2: 4-ch pressure clamp terminal block, analog input, CENTUM CS 3000 / VP compatible
• STB4D-00: 4-ch screw-type terminal block, analog input, standard field wiring interface
• STB4D-10: 4-ch terminal block with built-in fuse protection, analog input modules
• STB4D-20: 4-ch terminal block with surge protection, for field environments with transient risk
• STB4D-30: 4-ch terminal block with Zener barrier integration, intrinsically safe applications
• STB4D-40: 4-ch terminal block with galvanic isolator interface, hazardous area wiring

Analog Output Terminal Blocks

• STB4E-00: 4-ch screw-type terminal block, analog output, current loop 4–20 mA
• STB4E-00 S2: 4-ch pressure clamp terminal block, analog output variant
• STB4E-10: 4-ch terminal block with fuse, analog output, field device protection

Digital Input Terminal Blocks

• STB8D-00: 8-ch screw-type terminal block, digital input, 24 VDC dry contact
• STB8D-00 S2: 8-ch pressure clamp terminal block, digital input, vibration-resistant
• STB8D-10: 8-ch terminal block with LED status indication per channel, digital input
• STB16D-00: 16-ch screw-type terminal block, digital input, high-density marshalling

Digital Output Terminal Blocks

• STB8E-00: 8-ch screw-type terminal block, digital output, relay or transistor output modules
• STB8E-00 S2: 8-ch pressure clamp terminal block, digital output, spring-clamp termination
• STB16E-00: 16-ch screw-type terminal block, digital output, high-density I/O marshalling

Thermocouple / RTD Input Terminal Blocks

• STB4T-00: 4-ch terminal block for thermocouple input modules, compensation cable compatible
• STB4T-00 S2: 4-ch pressure clamp thermocouple terminal block, reduced installation time
• STB4R-00: 4-ch terminal block for RTD (Pt100) input modules, 3-wire configuration

Sourcing Hard-to-Find & Obsolete STB Series Parts

A significant portion of the STB series — particularly screw-type variants from the CENTUM CS 3000 era — has transitioned out of Yokogawa's active production schedule. Plant operators running legacy CENTUM CS 3000 systems face a structural procurement challenge: the I/O modules remain functional and the control logic is intact, but field wiring termination components such as STB terminal blocks become the limiting factor in system longevity.

Quality Control for the STB Series Range

• Contact force verification: Pressure clamp (S2) variants are tested for spring-clamp retention force using calibrated insertion/extraction gauges to confirm compliance with IEC 60947-7-1 terminal block standards.
• Insulation resistance: Each terminal position is tested at 500 VDC to verify insulation resistance exceeds 100 MΩ, ruling out contamination or moisture ingress from storage.
• Dimensional conformance: DIN-rail mounting geometry and module connector pitch are verified against Yokogawa STB series mechanical drawings to ensure correct backplane mating.
• Visual and marking inspection: Terminal identification markings, color coding, and housing integrity are checked. Units with illegible markings or housing cracks are rejected.
• Functional loop test (where applicable): For terminal blocks with integrated fusing or surge protection (STB4D-10, STB4D-20), the protection element is verified for continuity and rated response characteristics.