Key Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | IS220PAOCH1B |
| Manufacturer | GE (General Electric) |
| Product Type | Analog I/O Pack (Output) |
| System Compatibility | GE Mark VIe Distributed I/O |
| Output Channels | 2x 0-20mA Current Loop |
| Resolution | 16-bit |
| Power Supply | 3-pin DC Input |
| Network Interface | 2x RJ45 Ethernet |
| Field Connection | DC-37 Pin Connector |
| Auto-Config | Supported (Controller Download) |
| Diagnostics | Front Panel LED Indicators |
| Application | Gas/Steam Turbine Control |
Product Introduction
The GE IS220PAOCH1B is an analog output I/O pack designed for the Mark VIe distributed control architecture. It serves as the electrical interface between the I/O Ethernet network and the field termination board, converting digital control commands into precise 0-20mA current loop signals for actuators and valves. This module is critical for maintaining turbine speed, fuel flow, and steam pressure in power generation applications.Unlike legacy I/O cards, the GE IS220PAOCH1B features an integrated processor that handles auto-configuration and diagnostics locally. When powered up, it reads its board ID and automatically downloads the correct application code from the controller, eliminating manual jumper settings. The module provides two independent 0-20mA outputs with 16-bit resolution, ensuring accurate positioning of critical turbine control elements even in high-noise environments.
Installation & Configuration Guide
Preparation (10 min)
Verify the GE IS220PAOCH1B matches the required revision for your Mark VIe system. Gather the specific DC-37 pin mating connector and ensure the 3-pin power supply is disconnected. Self-correction: Always check the terminal board compatibility first; this pack must mate with the correct analog output termination board (e.g., IS200STAOH series).Removal (5–10 min)
Remove power from the I/O pack slot. Disconnect the DC-37 field wiring harness and the dual RJ45 Ethernet cables. Release the top and bottom extraction levers. Pull the module straight out using the handles—do not twist. Inspect the backplane Ethernet pins for damage, as these are sensitive to misalignment.Installation (10 min)
Align the GE IS220PAOCH1B with the backplane guides. Slide in firmly until the extraction levers engage the backplane connectors. Secure the levers to lock the module. Reconnect the dual Ethernet cables (ensure correct port orientation for ring topology). Reconnect the DC-37 field wiring, verifying pin 1 alignment.Power-On & Test (10 min)
Apply 3-pin DC power. Observe the front panel LEDs: PWR (green), RUN (green), and FAULT (off). The module will automatically perform a self-test and request configuration from the controller. Use Mark VIe Workstation to verify the module is recognized and output values match the commanded setpoints. Force a 4mA and 20mA output to verify field loop continuity.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Immediate Action |
|---|---|---|
| FAULT LED Solid Red | Hardware failure or config mismatch | Cycle power. Check controller alarm log. |
| RUN LED Off, PWR Green | Firmware load failure | Verify Ethernet link and controller status. |
| Output Stuck at 0mA | Field loop open or 24V supply lost | Measure voltage at field terminal block. |
| Output Drifting | Ground loop or noise | Check shield grounding at termination board. |
| Auto-Config Failed | Board ID mismatch | Verify pack type matches controller config. |
Dimensions, Mounting & Wiring Notes
- Dimensions: Standard Mark VIe I/O Pack form factor
- Mounting: Backplane slot with extraction levers
- Terminal Notes: DC-37 connector for field I/O, 2x RJ45 for Ethernet, 3-pin for power. Real-world detail: The Ethernet ports are stacked; ensure the cable clips don’t interfere with adjacent modules in dense racks. If using the PAOCH2 variant, verify the high-current path is only used on Channel 1.
FAQ
What is the difference between IS220PAOCH1B and IS220PAOCH2?
The PAOCH2 includes additional hardware to support 0-200mA output on Channel 1. If your actuator requires high current, you must use the PAOCH2. Standard valve positioners typically use the IS220PAOCH1B.Can I hot-swap this module in a running Mark VIe system?
Yes, Mark VIe supports hot-swapping for I/O packs. However, always verify the field loop is in a safe state before removal, as outputs will go to 0mA during the swap.Do I need to manually configure jumpers on this pack?
No. The GE IS220PAOCH1B uses auto-configuration. The processor reads the board ID and downloads parameters from the controller. Manual configuration is only required if auto-config is disabled in the system settings.I replaced the pack but outputs are wrong. What now?
Check the termination board type in the controller configuration. If the system expects a different board type, the scaling will be incorrect. Also verify the 250Ω load resistor is present on the termination board for current loop outputs.How do I verify the Ethernet ring is healthy?
Check the link LEDs on both RJ45 ports. Both should be green. Use the Mark VIe diagnostic tool to verify ring integrity. A single broken cable won’t stop communication, but dual failures will isolate the pack.Is this module compatible with Mark VI (non-e)?
No. The IS220PAOCH1B is specifically designed for Mark VIe. Mark VI systems use different I/O pack architectures. Do not attempt to install this in a legacy Mark VI rack.What power supply does this module require?
The GE IS220PAOCH1B requires a regulated 24V DC supply via the 3-pin connector. Ensure the power supply can handle the inrush current during startup and maintain voltage within ±5% under full load.
