IC693CPU341T GE Series 90-30 CPU | 80 KB Memory, 20 MHz

What Happens When a Legacy Controller Fails Mid-Production?

When a Series 90-30 CPU faults on a running line, every downstream station stops. The IC693CPU341T is the revision T mid-range modular CPU for that platform. It pairs an Intel 80C188XL processor with 80 KB of user program memory. Consequently, it remains a common target for exact-match replacement in legacy GE Fanuc installations. Emerson now owns the product line, and the part is discontinued (End of Sale). This part has been discontinued by the manufacturer. Migrate to PACSystems RX3i (IC695 series); we stock remaining new and refurbished units.

IC693CPU341T Technical Specifications

The table below lists verified parameters for this single-slot CPU module. Each value traces directly to the revision T datasheet.

• Processor: Intel 80C188XL
• Clock Speed: 20 MHz
• User Program Memory: 80 KB
• Register Memory (%R): 9999 words
• Discrete Global Memory (%G): 1280 bits
• Discrete I/O Capacity: 512 inputs / 512 outputs
• Serial Ports: 1
• Supply Voltage: 5 VDC (backplane)
• Slot Width: Single slot

Because the module draws 5 VDC from the backplane, it does not require an external power supply. Meanwhile, the 80 KB user memory supports mid-range logic programs. In addition, the 9999-word register space handles data manipulation and math operations. The 1280-bit global memory allows efficient peer-to-peer data sharing across the rack. However, no communication protocols beyond the single serial port are documented in the available data.

Failure Modes and Reliability in Aging Systems

Discontinued CPUs typically fail at the power regulation stage or through memory corruption. For example, backplane capacitor degradation can cause intermittent 5 VDC supply faults. Similarly, battery-backed RAM may lose program data if the backup cell weakens. Consequently, inspect the module periodically for physical damage and verify program retention after power cycles. Since the IC693CPU341T is no longer in production, stocking a verified spare reduces unplanned downtime. Above all, follow the manufacturer's safety manual during any inspection.

Integration with Series 90-30 Racks

The IC693CPU341T occupies a single slot in a Series 90-30 backplane. It communicates through one serial port for programming and peripheral connections. If your application uses a fieldbus network, wiring into such networks may require an external gateway or connection module. Therefore, confirm cables and gateways with the supplier before installation. Additionally, verify that the rack power supply delivers the required 5 VDC backplane voltage. Because the module is discontinued, confirm compatibility with your existing I/O modules and rack revision.