GE IC694ALG390A | High-Speed Analog Input Module | PACSystems RX3i | Genuine New

Part Number: IC694ALG390A | Brand: GE Intelligent Platforms (now Emerson / Proficy) | Platform: PACSystems RX3i | Condition: Genuine New Original

The Short Version

8-channel, 16-bit analog input module for GE PACSystems RX3i racks. Supports voltage (±10 V, 0–10 V) and current (4–20 mA) inputs with a 250 µs per-channel scan rate — the fastest analog input module in the IC694 series. Genuine new unit, in stock.

What Makes This Module "High-Speed"?

Most standard analog input modules in the PACSystems RX3i family scan at 1 ms to 10 ms per channel. The IC694ALG390A achieves 250 µs per channel — four to forty times faster. This matters in applications where the physical process changes faster than a standard analog module can track: high-speed pressure transients, flow rate monitoring on fast-cycling valves, vibration enveloping, or closed-loop servo feedback where analog sensor data must feed back to the control loop within a single PLC scan.

If your application can tolerate a 5–10 ms analog scan, a standard IC694ALG221 or IC694ALG222 will serve it adequately. If you need to capture events that resolve in under 1 ms, or maintain tight closed-loop control at high update rates, the IC694ALG390A is the correct module.

Technical Specifications

Parameter	Specification
Part Number	IC694ALG390A
Manufacturer	GE Intelligent Platforms
Platform	PACSystems RX3i
Module Type	High-speed analog input
Number of Channels	8 single-ended (configurable)
Input Signal Ranges	0–10 V DC, ±10 V DC, 4–20 mA
A/D Resolution	16-bit (1 part in 65,536)
Scan Rate	250 µs per channel
Input Impedance (Voltage)	> 1 MΩ
Input Impedance (Current)	250 Ω
Overall Accuracy	±0.1% of full scale (at 25 °C)
Temperature Drift	±50 ppm/°C typical
Channel Isolation	Channel-to-backplane isolated
Power Consumption	From RX3i backplane (no external supply required)
Backplane Compatibility	IC694 / IC695 RX3i racks
Operating Temperature	0 °C to 60 °C
Storage Temperature	−40 °C to +85 °C
Relative Humidity	5–95% non-condensing
Agency Approvals	UL, CE
Configuration Tool	Proficy Machine Edition (PME)
Condition	Genuine new original

Understanding the IC694 Module Numbering

The IC694ALG390A follows GE's standard module naming convention:

Segment	Meaning
IC694	PACSystems RX3i I/O family
AL	Analog (as opposed to DI = digital input, DO = digital output)
G	General purpose I/O module
390	Product variant code — identifies this as the high-speed 8-channel AI module
A	Revision level A

The "A" suffix at the end is the hardware revision designator. If a later revision (e.g. IC694ALG390B) exists, it is functionally equivalent and backward compatible unless GE's release notes specifically indicate otherwise.

Where IC694ALG390A Is the Right Choice

Not every application needs a high-speed analog module. Here is a practical guide to when this module earns its place:

✅ Use IC694ALG390A when:

Closed-loop control loops run at scan rates under 1 ms and require analog feedback within that window
Monitoring fast-changing process variables: pressure surges, flow transients, rapid temperature changes in induction heating
Performing waveform capture or envelope detection on vibration sensors
Implementing torque or force feedback in servo and motion applications where the analog signal must update faster than a standard module can deliver
Replacing a failed IC694ALG390A on an existing system where the application was originally engineered for high-speed acquisition

⚠️ Standard analog modules may be sufficient when:

Process variables change slowly (temperature in a tank, level in a vessel, slow-moving pressure systems)
Scan rates of 1–10 ms are acceptable
Budget constraints favour the lower-cost IC694ALG221/222 range

System Architecture — Where This Module Sits

RX3i Backplane (IC695CHS016 or similar)
│
├── CPU Module (IC695CPE302 / CPE305 / CPU315 etc.)
├── Power Supply (IC695PSA140 / IC694PWR321 etc.)
├── [IC694ALG390A] ← This module (slots 1–12, any standard I/O slot)
│     8 × Analog Inputs (voltage or current)
│     Connected to: pressure transducers, flow meters,
│                   load cells, servo feedback signals,
│                   temperature transmitters (4–20 mA)
└── Other I/O modules as required

The IC694ALG390A draws its power entirely from the RX3i backplane — no separate field power supply is required for the module itself. Field sensor power (24 V DC for transmitters) is supplied separately per the sensor wiring requirements.

IC694ALG390A vs Standard RX3i Analog Input Modules

Feature	IC694ALG390A	IC694ALG221	IC694ALG222
Channels	8	4	8
Resolution	16-bit	15-bit	15-bit
Scan Rate	250 µs / channel	~1 ms / channel	~1 ms / channel
Voltage Ranges	±10 V, 0–10 V	±10 V, 0–10 V	±10 V, 0–10 V
Current Range	4–20 mA	4–20 mA	4–20 mA
Isolation	Channel-to-backplane	Channel-to-backplane	Channel-to-backplane
Best For	Fast process / closed-loop	Standard process	Standard process
Relative Cost	Higher	Lower	Lower

Rule of thumb: If your application requires the IC694ALG390A's speed, the higher cost is justified by the performance requirement. If it does not, the IC694ALG221/222 series offers equivalent accuracy at lower cost.

Configuration with Proficy Machine Edition

The IC694ALG390A is configured in Proficy Machine Edition (PME) software, GE's programming and configuration environment for PACSystems. The module appears in the hardware configuration tree when the RX3i rack is set up. Key configuration parameters per channel include input range selection (voltage or current), scaling to engineering units, alarm limits, and filter settings. No DIP switches or jumpers are required — all configuration is software-defined and stored in the CPU.

After configuration, analog input values appear as floating-point or integer values in the PLC's reference memory, accessible from the ladder logic or structured text program. GE's PME also supports online monitoring of analog channel values during commissioning, simplifying sensor calibration and loop verification.

Practical Installation Notes

A few things worth knowing before you install this module.

Wiring: The IC694ALG390A uses a removable terminal block (included). Each channel has dedicated input terminals plus a shield/drain terminal. For current inputs (4–20 mA), ensure the transmitter loop is powered correctly and that the 250 Ω input impedance is compatible with the transmitter's maximum loop voltage budget.

Shielding: At 250 µs scan rates, the module is sensitive to electrical noise. Use shielded twisted-pair cable for all analog inputs, terminate the shield at the module end only (not at both ends), and maintain physical separation from high-current power cables in cable trays.

Grounding: Ensure the RX3i rack is properly grounded to the control cabinet earth rail. Floating or poorly grounded racks increase susceptibility to common-mode noise, which at high scan rates can appear as measurement jitter.

Firmware: Confirm that the RX3i CPU firmware version supports the IC694ALG390A. Older CPU firmware revisions may not recognise this module. Check GE's compatibility matrix in the PACSystems RX3i Hardware and Installation Manual (GFK-2314) before deployment.

Genuine GE Module vs Third-Party or Counterfeit Risk

High-value automation modules like the IC694ALG390A are occasionally available from sources offering "equivalent" or unlabelled substitutes. For a high-speed analog input module, the risks of non-genuine units are particularly significant:

Risk Factor	Genuine GE IC694ALG390A	Non-Genuine / Substitute
Scan rate actually achieves 250 µs	✅ Factory verified	❌ Unverifiable
16-bit ADC resolution confirmed	✅	❌ May use lower-resolution ADC
PME hardware configuration compatibility	✅ Recognised by PME	❌ May not configure correctly
Backplane communication protocol	✅ GE proprietary protocol, correct	❌ Risk of communication errors
CE / UL compliance documentation	✅	❌ None
Warranty and RMA support	✅	❌ None

For production-critical RX3i systems, specifying a genuine GE module is the only way to ensure that the module's performance matches the application requirement.

Ordering & Delivery

✅ Genuine GE IC694ALG390A — new original, not refurbished
✅ In Stock — dispatches within 1–3 working days
✅ Global Shipping — DHL / FedEx / UPS with full tracking
✅ ESD-protective packaging for safe transit of sensitive electronics
✅ Volume pricing available for spare parts programmes and system builds
✅ Pre-order compatibility advice available — contact us with your CPU and firmware version

Frequently Asked Questions

Q1: What does "high-speed" mean for the IC694ALG390A, and how does it differ from standard GE analog modules? The IC694ALG390A samples each analog input channel at 250 µs, compared to approximately 1–10 ms for standard RX3i analog input modules such as the IC694ALG221 or IC694ALG222. This means the IC694ALG390A can capture and report four to forty times more analog data points per second, enabling closed-loop control at faster update rates and accurate capture of process transients that a standard module would miss or alias.

Q2: Is the IC694ALG390A compatible with IC694 backplanes as well as IC695 backplanes? Yes. The IC694ALG390A is designed for the PACSystems RX3i platform and is compatible with both IC694-series and IC695-series RX3i backplanes. It can be installed in any standard I/O slot in an RX3i rack alongside IC694 and IC695 modules. It is not compatible with the older Series 90-30 (IC693 family) backplanes — those use a different backplane bus and mechanical form factor.

Q3: How many channels does the IC694ALG390A have, and can individual channels be independently configured? The module has 8 analog input channels. Each channel can be independently configured in Proficy Machine Edition for input type (voltage or current) and range (±10 V, 0–10 V, or 4–20 mA). This means you can mix voltage and current inputs on the same module — for example, channels 1–4 for 4–20 mA pressure transmitters and channels 5–8 for ±10 V velocity feedback signals from servo drives.

Q4: What is 16-bit resolution in practical terms? 16-bit resolution means the analog-to-digital converter divides the full input range into 2¹⁶ = 65,536 discrete steps. For a ±10 V range, this gives a resolution of 20 V ÷ 65,536 ≈ 0.305 mV per step. For a 4–20 mA range, it gives 16 mA ÷ 65,536 ≈ 0.244 µA per step. In practice, the usable resolution is limited by noise and accuracy — the module's ±0.1% full-scale accuracy corresponds to ±65 counts on a 16-bit scale. This is significantly better than 12-bit (4,096 steps) or 15-bit modules and matters in applications requiring fine differentiation of analog signal levels, such as weighing, precise flow control, or position feedback.

Q5: What software is needed to configure the IC694ALG390A? The IC694ALG390A is configured using GE Proficy Machine Edition (PME), which is the standard programming and configuration tool for the PACSystems RX3i platform. PME is available from GE/Emerson. Within PME, the module is added to the hardware configuration for the target RX3i rack and slot, and each channel's input range, scaling, and alarm parameters are set through the module's configuration dialogue. No separate configuration software or hardware tools are needed beyond PME and a standard Ethernet connection to the RX3i CPU.

Q6: Does the IC694ALG390A require external power for the module or field side? The module itself draws all of its operating power from the RX3i backplane — no external module supply is required. Field-side power for connected sensors (e.g. 24 V DC loop power for 4–20 mA transmitters) must be provided externally as part of the instrument wiring design. The module provides no loop power to field devices.

Q7: What types of sensors or transmitters are typically connected to this module? Typical field devices connected to the IC694ALG390A include 4–20 mA process transmitters (pressure, flow, level, temperature), ±10 V analogue output devices (servo drive velocity references, weigh cell amplifiers, position transducer outputs), potentiometers, and signal conditioners. At 250 µs scan rates, it is also suitable for higher-frequency analogue signals in vibration monitoring, force measurement, and fast pressure or flow transient capture.

Q8: Can this module be used as a direct replacement for a failed IC694ALG390A without reconfiguring the PLC program? In most cases, yes. If you are replacing a failed IC694ALG390A with a new genuine unit of the same revision, the existing PME hardware configuration and PLC program require no changes — the replacement module is recognised automatically by the CPU using the stored configuration. If the hardware revision differs (e.g. replacing an older revision with a later one), verify GE's compatibility notes, but in practice RX3i module revisions are backward compatible within the same part number family.

Q9: Is this module available new, or only as refurbished/used stock? This is a genuine new original GE module — it has never been installed in a rack, never been powered, and has not been refurbished or remanufactured. Given the $546 price point and the critical nature of analog input modules in production systems, we do not sell used or reconditioned RX3i modules.

Q10: What warranty and support do you offer? All modules are supplied with our standard warranty covering manufacturing defects. For post-purchase technical questions about installation and configuration in your specific RX3i system, our team can provide guidance based on 15+ years of experience supplying GE PACSystems components. Contact us via email or WhatsApp for support. For Proficy Machine Edition software licences and GE factory technical support contracts, contact GE/Emerson directly.

IC694ALG390A Genuine IC694ALG390A GE High Speed Module