IS220PDIOH1B REV. B: Don't Let a Reseller Sticker Decide Your Terminal Board

A real field case involving this exact pack type is worth knowing before you order one. A site had a PDIO fail on the <R> channel of a TMR Mark VIe panel and pulled a spare from stock. The spare pack, though functionally identical, carried a sticker calling out use with a 24 V terminal board, while the plant's actual terminal board ran at 125 V. The site swapped terminal board hardware to match the sticker — and the download stopped working. The pack itself was never the problem: PDIO packs are interchangeable across the whole family of TDBS/TDBT terminal boards, but each specific terminal board is only built for one field voltage, and a reseller's sticker is not a substitute for checking what's actually bolted into your cabinet.

PDIO is GE's Speedtronic Mark VIe pack that combines discrete contact input and relay output on one assembly — the functional equivalent of a PDIA and a PDOA pack built together. It reads up to 24 contact inputs, drives up to 12 relay outputs, and reports terminal-board-specific feedback to the <R>, <S>, or <T> controller over IONet through dual RJ-45 ports, per GE's GEH-6721 Mark VIe Control System Guide. Discrete signals pass to the terminal board through a DC-62 connector; a three-pin connector supplies pack power.

The H1B hardware generation extends compatibility to terminal boards built for hazardous-location installations — combinations documented as Intrinsically Safe Apparatus, approved for Class I Division 2 Groups A-D, Class I Zone 2 Group IIC, and ATEX Zone 2 Group IIC per GE's GEH-6725 certification documentation, in addition to the standard-duty terminal boards used with earlier generations.

What Actually Needs Matching Before You Order

• The PDIO pack itself (H1A or H1B) is interchangeable across the IS200TDBS/IS200TDBT terminal board family — but the terminal board is voltage-specific. A 24 V board and a 125 V board are not interchangeable, and forcing one onto field wiring built for the other risks damaging it.
• Your ToolboxST configuration must match the terminal board hardware actually installed. A download that "won't go through" after a hardware swap is very often a configuration mismatch, not a bad pack.
• Distinguish a Process Alarm (a bad field value) from a Diagnostic Alarm (a communications or hardware fault) before deciding what to replace.
• Confirm Simplex, Dual, or TMR configuration, since a TMR panel needs three packs (one per <R>/<S>/<T>) and losing one doesn't necessarily take the channel down the way it would in Simplex.
• Check IONet cabling and connectors for corrosion or a poor bend radius, and rule out heat buildup in the cabinet before ordering a replacement pack outright.

What REV. B and the Suffix Tell You

IS220 marks a Mark VIe distributed I/O pack, PDIO the combined input/output function, H1 the design generation, B the hardware revision beyond the original H1A, and REV. B the board revision within this part number. Match all of it, plus your terminal board's voltage rating, before ordering. Our GE Speedtronic Part Number Decoder covers GE's naming convention in full.

Where This Pack Fits

PDIO pairs with the TDBS (Simplex) or TDBT (TMR) terminal board family. Where a panel needs only contact inputs or only relay outputs, the related packs are PDIA and PDOA respectively. Our GE Mark VI IS200 Boards collection lists compatible terminal boards.

Details to Send With Your Request

• Full part number with suffix and revision (IS220PDIOH1B REV. B)
• A photo of the label
• The terminal board part number actually installed in your cabinet, if known
• Turbine model and Mark control generation
• Quantity and urgency

We reply within 24 hours, ship worldwide DDP, and accept purchase orders. Request a Quote and our team will confirm fit and availability — this store does not publish prices online.

General Information about the Product
Part Number	IS220PDIOH1B Mark VI IS220
Description	GE General Electric IS220PDIOH1B REV. B I/O Pack Module Mark VI
Condition	used Cleaned and Tested. With 1 Year Warranty.