IS220PAICH2A: The 200 mA Output Variant of the PAIC Pack

What separates an H2 pack from an H1 pack is one specific piece of hardware: an add-on daughterboard that gives analog output 1 a 0-200 mA range, on top of the standard 0-20 mA. Power for that 200 mA circuit is drawn from a variable voltage source on the daughterboard specifically to keep the linear output transistor from overheating — a deliberate design choice, not a workaround. Everything else about the PAICH2A is the same PAIC pack used across GE's Speedtronic Mark VIe (and Mark VIeS) fleet: it mounts directly on an analog input terminal board via a single DC-37 pin connector and talks to the <R>, <S>, or <T> controller over IONet through dual RJ-45 ports.

On the input side, this pack still reads 10 analog inputs — eight configurable to 5 V, 10 V, or 4-20 mA current loop, and two more to ±1 mA or 4-20 mA — through a 16-bit A/D converter, with a normal scan time of 5 ms (200 Hz). Output conversion runs through a 14-bit D/A converter at 0.5% accuracy. The current-loop load resistors for the inputs are mounted on the terminal board, not inside the pack. GE also documents a compressor-stall detection function tied to this analog channel set, which is one reason the 200 mA output range matters on some applications — certain actuators and positioners expect that higher current range rather than the standard 0-20 mA loop.

Diagnose First: Pack, Terminal Board, or Field Device?

• Check the terminal board before the pack — load resistors and field wiring live there, and a drifting resistor reads exactly like a failed input channel.
• If output 1 isn't reaching its commanded value, confirm what range the connected actuator actually expects (0-20 mA vs 0-200 mA) before assuming the daughterboard has failed — a mismatched configuration looks like a hardware fault.
• Run the swap test: move the suspect pack to a known-good terminal board, or a known-good pack onto the suspect board, and see which one the problem follows.
• Rule out the IONet: verify both Ethernet ports are linked, inspect cabling and switch health, since a network fault presents the same as a dead pack from the control room.
• Confirm the terminal board revision is one this pack is designed to run on — a mismatch throws a compatibility alarm, which is not the same thing as a hardware failure.
• A suicide-relay or output-stage alarm is a genuine pack-level fault and one of the few symptoms where pack replacement, not rewiring, is the correct fix.

What H2A Means on the Label

IS220 marks a Mark VIe distributed I/O pack, PAIC is the analog function, H2 is the design generation with the 200 mA output daughterboard (versus the two-output, 0-20 mA-only H1 generation), and the trailing A marks this pack's processor/hardware revision. Confirm the full string against your terminal board and ControlST project before ordering — an H2 pack and an H1 pack are not interchangeable if your application actually uses the 200 mA range. Our GE Speedtronic Part Number Decoder breaks down how to read every segment of the part number.

Related Packs and Terminal Boards

PAICH2A pairs with TBAI/STAI-family analog terminal boards, the same family used by the H1 packs. If your panel needs discrete signals rather than analog on the same IONet segment, see the related PDIA, PDOA, and PDIO packs. Browse our GE Mark VI IS200 Boards collection to check what else pairs with your terminal boards.

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