IS220PAICH1B REV. B: The Second-Generation PAIC Analog Pack

The H1B suffix is not just a revision bump — it is the second hardware generation of the PAIC analog I/O pack, built around a BPPC processor board rather than the BPPB board used in the original H1A. The two are functionally compatible, but the BPPC board requires ControlST V04.03 or later to be fully supported, and this pack also runs on a lower minimum supply voltage than the original H1A design. Nominal power is 24 or 28 V dc either way.

Beyond the processor change, the PAIC's job in a Mark VIe (or Mark VIeS) cabinet is unchanged: it is the analog I/O pack that mounts directly on an analog input terminal board and exchanges data with the <R>, <S>, or <T> controller over the IONet via dual RJ-45 ports. Ten analog inputs (eight configurable to 5 V/10 V/4-20 mA, two more to ±1 mA/4-20 mA) and two 0-20 mA current outputs run through a 16-bit A/D converter and 14-bit D/A converter, at a normal 5 ms (200 Hz) scan rate. A single DC-37 pin connector carries all of this to the terminal board, where the current-loop load resistors physically reside.

How to Tell If the Pack Itself Has Failed

Because the acquisition electronics for analog signals split between the terminal board and the pack, do not assume a bad reading means a bad PAIC:

• Check the terminal board and field wiring first — the load resistors and field terminals are on the board, and a drifted resistor or loose connection reads exactly like a dead input channel.
• Run the swap test: install the suspect pack on a known-good terminal board (or vice versa). The fault following the pack confirms the pack; the fault staying put confirms the board or wiring.
• Check IONet connectivity — both Ethernet ports, cable condition, and switch health — before condemning the pack, since a lost network path shows up the same way a dead pack does.
• Confirm terminal board revision compatibility. A PAICH1B expects a matched terminal board revision; a mismatch reports as a compatibility alarm, not a hardware failure.
• One alarm that does point squarely at this pack: a suicide-relay fault on an output, indicating either a command/feedback mismatch or a relay failure on the acquisition board itself. That is a genuine pack-level issue, and the fix is the pack, not the wiring.

Decoding IS220PAICH1B REV. B

IS220 = Mark VIe distributed I/O pack, PAIC = analog I/O function, H1 = base two-output design generation, B = the BPPC-based hardware revision described above, and REV. B is the board revision within this specific part number. All of it needs to match your terminal board and control software version — an H1B pack is not a blind swap for an H1A pack if your ControlST project or terminal board hasn't been updated to match. See our GE Speedtronic Part Number Decoder for the full breakdown of GE's Speedtronic numbering.

Related Packs and Boards

PAICH1B pairs with analog input terminal boards in the TBAI/STAI family. If you're not certain whether your system needs an H1A or H1B, or whether a different analog or discrete pack is the right match, our GE Mark VI IS200 Boards collection is a good place to cross-reference part numbers side by side.

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General Information about the Product
Part Number	IS220PAICH1B Mark VI IS220
Description	GE General Electric IS220PAICH1B REV. B Power Distribution Pack Mark VI
Condition	used Cleaned and Tested. With 1 Year Warranty.