Key Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | IS220PAICH2A / 336A4940CSP11 |
| Product Type | Mark VIe Analog I/O Pack (PAIC) |
| Compatible System | GE Mark VIe Speedtronic control system |
| Analog Inputs | 10 channels total |
| Input Range | Ch 1–8: 5 V, 10 V, or 4–20 mA; Ch 9–10: 1 mA or 4–20 mA |
| Analog Outputs | 2 channels, 0–20 mA; Output 1 supports additional 0–200 mA hardware option |
| Supply Voltage | 28 V DC, approx. 0.81 A |
| Communication | Dual RJ-45 Ethernet (I/O Ethernet to controller) |
| Terminal Interface | DC-37 connector to Mark VIe terminal board |
| Configuration | ToolboxST |
| Operating Temperature | -30°C to +65°C (conformal-coated PCB) |
| Certifications | UL/CSA listed; ATEX Class I Div 2 / Zone 2 variants exist |
| Hot Swap | Supported per Mark VIe I/O pack design |
Product Introduction
Analog I/O packs are where control logic meets the real world. If the inputs drift or the outputs saturate, the turbine or process controller is making decisions on bad data. The GE IS220PAICH2A is a Mark VIe PAIC analog I/O pack used in Speedtronic turbine and process control applications. It mounts directly to a Mark VIe terminal board through a DC-37 connector and talks to the controller over dual Ethernet links.Field engineers keep this pack in rotation because it consolidates ten analog inputs and two analog outputs in one I/O Ethernet node. The first eight inputs can be configured as 5 V, 10 V, or 4–20 mA, while the last two handle low-current 1 mA or 4–20 mA signals. The two 0–20 mA outputs are useful for driving recorders, actuators, or external controllers, with Output 1 offering a 0–200 mA hardware option. One thing I always check before swapping: the terminal board revision and shunt/jumper settings. The I/O pack itself is usually solid; the terminal board wiring is where configuration errors hide.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
- Visual inspection — check PCB revision, conformal coating, connector pins, and label.
- Counterfeit check — compare label format, revision marking, and mechanical dimensions.
- Power-up test — apply 28 V DC through the three-pin supply connector.
- Ethernet link check — verify link/activity LEDs on ENET1 and ENET2.
- I/O verification — simulate 4–20 mA and voltage inputs; verify output current with a Fluke 115 or equivalent.
- Terminal board fit — confirm clean mating with the DC-37 connector.
- Documentation — photograph label, revision, serial number, and test readings before packing.
The Engineer’s Warning (Pitfalls)Do not confuse input channels. Channels 1–8 support voltage or 4–20 mA, but channels 9–10 are low-current inputs. If you wire a 4–20 mA loop expecting the same scaling as the first eight channels without checking the terminal board and ToolboxST configuration, the reading will be wrong. I have seen a commissioning team spend six hours chasing a “bad sensor” that was actually a channel 9 input configured for 1 mA instead of 4–20 mA.Also, the 0–200 mA option on Output 1 is hardware-dependent. Do not assume every IS220PAICH2A can source 200 mA just because the manual mentions it. Check the board revision and hardware option before connecting high-current loads.
Installation & Configuration Guide
Pre-Installation ⚠️
- Verify the Mark VIe controller and I/O node are in a safe state.
- Photograph the existing I/O pack label, terminal board wiring, shunts, and Ethernet port assignments.
- Confirm the replacement pack matches IS220PAICH2A / 336A4940CSP11.
- Check that the terminal board is the correct type for PAICH2.
Removal
- Document alarm status and I/O values before removal.
- Disconnect Ethernet cables.
- Remove the three-pin power connector.
- Unfasten the mechanical retaining studs near the Ethernet ports.
- Pull the I/O pack straight out of the DC-37 connector.
Installation
- Verify the terminal board and channel configuration before powering up.
- Inspect the DC-37 connector for bent pins or contamination.
- Seat the I/O pack firmly onto the terminal board.
- Reinstall the mechanical retaining studs to avoid stress on the DC-37 connector.
- Reconnect the 28 V DC power connector.
- Reconnect Ethernet cables to the correct ports.
Power-On & Testing
- Apply 28 V DC and check LED status.
- Verify Ethernet communication with the Mark VIe controller.
- Use ToolboxST to confirm I/O pack recognition and firmware/revision match.
- Test each analog input with a known source.
- Verify both analog outputs under controlled conditions.
- Return the I/O node to service only after all channels are validated.
Compatible Replacement Models
- ✅ IS220PAICH2A (same revision) — Direct replacement. Matches existing terminal board and ToolboxST configuration when the revision is identical.
- ⚠️ IS220PAICH2A (different revision) — Usually hardware-compatible, but may require ToolboxST verification, firmware alignment, or channel scaling checks. Plan for 30–60 minutes of engineering review.
- ❌ Non-PAIC Mark VIe I/O packs (PDIO, PDAH, PTUR, etc.) — Not compatible. Different signal types, terminal boards, and logic mapping. Do not substitute without a full system redesign.
Frequently Asked Questions (FAQ)
Can I hot-swap the IS220PAICH2A?
Yes. Mark VIe I/O packs are designed for hot replacement. Still, follow site procedure. Remove Ethernet and power cleanly, and avoid forcing the DC-37 connector.What does 336A4940CSP11 mean?
It is the GE assembly or procurement number associated with the IS220PAICH2A I/O pack. The functional part number is IS220PAICH2A.How many analog inputs does it have?
Ten. Channels 1–8 can be configured as 5 V, 10 V, or 4–20 mA. Channels 9–10 are 1 mA or 4–20 mA.Can both outputs drive 200 mA?
No. Only Output 1 has the additional hardware option for 0–200 mA. Output 2 is 0–20 mA unless otherwise specified by the board revision.What software configures this pack?
ToolboxST. The I/O pack must match the installed Mark VIe configuration, terminal board type, and channel scaling.What supply voltage does it need?
28 V DC, typically around 0.81 A, through the three-pin I/O pack power connector.Will any Mark VIe terminal board work?
No. The terminal board must support PAICH2 analog I/O. Using the wrong terminal board can cause open circuits, incorrect scaling, or connector damage.
