IS220PAOCH1B analog output I/O pack overview

The IS220PAOCH1B is a later revision of the Mark VIe analog output (PAOC) pack. Like the rest of the family it drives eight simplex 0-20 mA current-loop outputs with per-channel current feedback, interfacing one or two IONet Ethernet networks to a GE analog output terminal board through a DC-37 connector. What sets the H1B apart is its processor board: it uses the BPPC, which is functionally compatible with the earlier BPPB but requires ControlST software V04.06 or later. Rated for a wide ambient range — GE specifies -40 to 70 °C (-40 to 158 °F) for the H1B, measured at the outside of the pack — it is a common choice for both new builds and like-for-like replacement of older PAOC packs, subject to the application de-rating GE specifies for dense output configurations.

Where the PAOC sits in the Mark VIe I/O chain

In a Mark VIe system the analog output pack is a distributed node: it mounts directly on its analog output terminal board, connects to the controller over IONet, and carries its own processor, acquisition board, temperature sensor, and self-diagnostics. Each of the eight outputs is driven by a 16-bit DAC through an external transistor amplifier, and each has a mechanical enable relay that can open the loop to the field load, with an LED showing the relay state. Typical destinations are valve positioners, I/P transducers, and indicators. Dual RJ-45 Ethernet ports and a soft-start three-pin power input complete the connections.

Self-tests, alarms, and what they tell you before you buy

Before you decide the pack is bad, let its diagnostics do the talking. The PAOC continuously verifies its internal power supply, checks that the electronic IDs of the CPU, acquisition, and terminal boards match the loaded application, and compares the current it senses on the terminal-board burden resistor against the commanded value. Use that to localize the fault:

• One channel off, others fine: suspect the field wiring, the connected load, or that channel on the terminal board, not the pack.
• Every active channel unhealthy with a valid 0-20 mA command: a pack or terminal-board hardware failure is likely, and the two are replaced together.
• Feedback wrong but output present: look at the burden resistor and terminal-board sense path.
• Loop open: confirm the channel enable relay is energized before anything else.
• Whole pack dark or offline: check power and IONet first.

Confirming the fault this way keeps you from buying a pack you did not need, and makes sure that when you do buy one, it fixes the problem.

H1B, BPPC, and ControlST compatibility

Reading the number: IS220 is the Mark VIe distributed I/O platform, PAOC is the analog output function, and H1B is the hardware revision — the BPPC-based successor to the BPPB-based H1A. If your label carries a further trailing character (for example an added dash letter), that denotes an additional hardware revision, so match the full designation on your unit exactly and confirm you are on ControlST V04.06 or later. Our GE Speedtronic Part Number Decoder explains each field of the number.

Related boards and cross-generation guidance

Keep the PAOC in context with the rest of your Mark VIe spares. The GE Mark VI IS200 Boards and GE Speedtronic Turbine Control Boards collections cover the companion analog, discrete, servo, and protection hardware, and the Mark V vs Mark VI: DS200 to IS200 guide helps if you are mapping analog output functions from an older control.

Getting an accurate quote

Send these with your request:

• The full part number exactly as printed (IS220PAOCH1B and any trailing revision) plus the board revision.
• A photo of the pack label.
• Turbine model and Mark VIe or Mark VI generation.
• Quantity and required delivery timing.

This is a new-surplus, factory-packaged unit; the exact condition and warranty are stated in the table below.

Request your IS220PAOCH1B quote

Hit Request a Quote, include the details above, and we will respond within 24 hours. Worldwide DDP shipping and purchase orders from qualified organizations are welcome.