Product Introduction
In a plant where a controller failure can mean six-figure losses per hour, the GE IC695CRU320 is the component you hope never fails—but need to replace instantly when it does. This CPU module acts as the brain for the PACSystems RX3i platform, a workhorse in industries from water treatment to automotive manufacturing. It’s not just a processor; it’s the decision-maker for your entire control rack.What sets this unit apart is its 300 MHz processor paired with 10 MB of user memory—plenty of headroom for complex logic without needing a high-end upgrade. In my experience, this specific model strikes the best balance between performance and cost for mid-range applications. It handles Ethernet communications natively, which simplifies integration with SCADA systems, though you’ll still need to verify your specific IP configuration if you’re swapping it into an existing network.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Processor Speed | 300 MHz |
| User Memory | 10 MB |
| Embedded Ethernet | 10/100 Mbps (RJ45) |
| Serial Ports | 1 x RS-232 (RJ45), 1 x RS-485 (Terminal Block) |
| Max Discrete I/O | 256 points (local) |
| Max Analog I/O | 128 points (local) |
| Backplane Compatibility | RX3i Universal Backplane (IC695/IC694) |
| Power Consumption | 3.5 W (5VDC backplane) |
| Battery Backup | Required for RAM retention (IC693ACC302 or equivalent) |
| Operating Temp | 0°C to 60°C (32°F to 140°F) |
| Programming Software | Proficy Machine Edition (v6.0 or later recommended) |
Application Scenarios & Pain Points
The real value of a spare IC695CRU320 isn’t realized during installation—it’s realized at 3:00 AM when the primary CPU faults out and the redundancy partner fails to take over. I recall a deployment at a municipal water plant where a voltage spike fried the main processor. Because they had a pre-configured IC695CRU320 on the shelf, they swapped it in under 20 minutes. Without that buffer stock, they would have faced a 48-hour lead time and a potential boil-water notice.
- Water/Wastewater Treatment: This is the bread and butter for this CPU. It handles the PID loops for chemical dosing and pump control effortlessly. If you are running a remote telemetry unit (RTU) setup, the dual serial ports on the IC695CRU320 allow you to talk to flow meters and SCADA radios simultaneously without buying extra comms modules.
- Automotive Assembly Lines: Speed matters here. The 300 MHz clock speed ensures scan times stay low even with heavy motion control logic. Are you worried about scan time jitter? This unit isolates communication tasks from logic execution, keeping your motion axes synchronized.
- Oil & Gas Midstream: For compressor stations, reliability is non-negotiable. This module supports the full suite of RX3i redundancy features. Just make sure your firmware matches across the primary and secondary racks, or the sync link won’t establish.
- Food & Beverage: In washdown environments, the CPU sits in a climate-controlled cabinet, but the RS-485 port is often used to poll legacy temperature sensors. It’s a solid bridge between old analog gauges and modern Ethernet/IP networks.
Case Study: A packaging facility in the Midwest faced intermittent faults on their main line controller. Diagnostics pointed to memory corruption on their aging CPU. They upgraded to a IC695CRU320 (replacing an older 200 MHz model). The extra memory headroom eliminated the overflow errors, and the line uptime increased from 92% to 99.5% in the first month.
Quality Control Process
We don’t just look at the box and ship it. Here is exactly what happens to this IC695CRU320 before it leaves our facility:
- Inbound Inspection: We verify the serial number against GE’s manufacturing date codes to ensure it’s not a grey market refurb disguised as new. We check the hologram on the side label—it should shift colors under light. If the plastic housing has yellowed, we reject it; that indicates UV damage or excessive heat exposure in a previous life.
- Live Functional Test: We slot the unit into an IC695CHS012 12-slot rack powered by an IC695PSD040 power supply.
- Power-Up: We verify the “OK” LED turns solid green within 5 seconds.
- Comms Check: We ping the default IP via Ethernet and establish a connection using Proficy Machine Edition.
- Memory Test: We write a dummy logic block to the RAM and read it back to verify integrity.
- Serial Loopback: We jumper the RS-232 port and send a test string to ensure the UART chip is functioning.
- Electrical Parameters: We measure the backplane power draw. It should sit steady around 0.7A at 5VDC. Any spikes indicate a failing capacitor on the PCB.
- Firmware Verification: We read the firmware version. Note: This unit ships with whatever version was last installed (often V3.0 or V4.0). It does not come with the latest firmware unless specified.
- Final QC: The battery cap is checked for tightness (a common failure point). We seal it in an anti-static bag with a desiccant pack.
Installation Pitfalls Guide
I’ve seen too many of these come back as “DOA” because of simple handling errors. Keep these in mind and you’ll cut 90% of your rework time.
- ❗ Firmware Version Mismatch: This is the number one headache. If your existing RX3i rack is running firmware V2.5 and you drop in a IC695CRU320 with V4.0, the other modules might not recognize it. The logic won’t download. Always check your system firmware before ordering, or be prepared to downgrade the CPU using a laptop.
- ❗ DIP Switch Configuration: Look at the side of the CPU. There are tiny DIP switches for boot options. If Switch 1 is ON, it forces a factory reset on boot. If you didn’t back up your logic, poof—it’s gone. Take a photo of the switch settings on your old CPU before you pull it out. Then take another one.
- ❗ Battery Dependency: This CPU uses volatile RAM for logic storage. It does not have internal flash for the user program (unless you have a specific memory card installed). If you swap the CPU and don’t have the battery installed immediately, or if the battery is dead, your logic is gone. You must download the program from your laptop. Don’t assume the logic is inside the box.
- ❗ Power Supply Headroom: The IC695CRU320 draws about 3.5W. If you are replacing an older, less powerful CPU, check your power supply budget. Adding high-current modules (like relay outputs) alongside this CPU might overload a marginal power supply, causing random drops.
- ❗ ESD Damage: The connectors on the front are sensitive. I watched a technician install one of these without a wrist strap, touched the Ethernet port, and fried the comms chip. It powered up fine, but wouldn’t go online. Don’t be that guy. Ground yourself.
