GE IS220PAOCH1A (Mark VIe Analog Output Module)
The 8-channel analog output module of the GE Mark VIe system is designed specifically for controlling gas/steam turbines, generators, and compressors. It outputs a 0-20mA current signal to drive valves, actuators, and instruments.

1、 Model and Identity
Model: IS220PAOCH1A (common version: REV D/J)
Brand/Series: GE/Mark VIe (Speedtronic)
Type: Analog Output Module (AO Pack)
Purpose: Turbine/generator control system (thermal power, hydropower, oil and gas, chemical industry)
2、 Core functions
8-channel high-precision current output: 0-20mA, driving regulating valve, excitation, baffle, speed/load set point.
System redundancy: Supports simplex/triple redundancy (TMR), combined with Mark VIe to achieve fault-tolerant control.
Real time communication: Dual Ethernet ports connected to the system network, completing I/O refresh and data voting within 40ms.
Fault self diagnosis: overcurrent/open circuit/short circuit detection, channel status reporting, SIFT software fault tolerance.
3、 Hardware specifications
1. Output channel
Number of channels: 8 (simplex)
Signal range: 0-20mA DC
Load capacity: Maximum 900 Ω
Accuracy: ± 0.5% (-30 ℃~+65 ℃)
Resolution: 16 bits
2. Electrical and Environmental
Power supply: 24VDC ± 20%, power consumption ≤ 18W
Temperature: -30 ℃ to+65 ℃
Protection: IP20, industrial cabinet installation
Size: Approximately 140 × 175 × 85mm (3U)
Weight: Approximately 2.1kg
3. Interface
Ethernet: 2 × 10/100Mbps (Mark VIe I/O network)
Terminal: screw type, convenient for on-site wiring
4、 Typical applications
Thermal power/gas turbine: speed control, load regulation, steam valve/fuel valve drive.
Generator excitation: AVR setting, reactive power regulation, excitation current control.
Compressor/pump: anti surge valve, reflux valve, pressure/flow setting.
DCS interface: Output 4-20mA working condition signals to third-party systems.
5、 Model positioning
IS220PAOCH1A (GE): 8-way AO, dedicated output for turbine/generator, focusing on valve/actuator drive.
IS420ESWDH1A (GE): Mark VIe switch, network forwarding only, no control/output function.
PCD235A/UFC921A (ABB): excitation/transmission main control+communication, focusing on generator excitation control.
TIOC-555HD (CCC): Compressor I/O+control, focusing on anti surge and speed control.