CPU Baseplate | GE Fanuc IC693CPU323U Series 90-30

The IC693CPU323U is a 10-slot embedded CPU baseplate designed for standalone control applications within the GE Fanuc Series 90-30 PLC platform. Featuring a 10 MHz 80188 microprocessor integrated directly onto the backplane board, it executes Boolean logic at a typical scan rate of 0.6 ms per 1K. The unit integrates a dedicated power supply slot alongside 10 expansion slots for I/O modules, delivering a compact, cost-effective baseplate architecture without requiring a separate CPU module in Slot 1.

Processor and Memory Allocation

The embedded CPU includes 12 Kbytes of user memory for program and data storage (6 Kbytes for firmware releases prior to Version 7.0). Primary memory is maintained via battery-backed RAM, with backup power supplied by the system power supply module plugged into the baseplate. Non-volatile EPROM or EEPROM memory chips can also be installed for program storage.

System memory address allocations support up to 320 discrete I/O points (maximum combined %I inputs and %Q outputs, capped at 160 %I inputs), 64 words of analog inputs (%AI), and 32 words of analog outputs (%AQ). Additional internal resources include 340 total timers/counters and support for shift register instructions.

System Architecture and Functional Limitations

Designed specifically for self-contained control setups, the IC693CPU323U does not support expansion baseplates or remote I/O racks. Because the RAM backup battery resides in the removable power supply module rather than on the CPU board itself, the system does not include a real-time (time-of-day) clock.

Additionally, the embedded processor architecture does not support logic interrupts or the I/O Override function available on modular Series 90-30 CPUs. Advanced communication modules such as PCM (Programmable Coprocessor Module) and CCM (Communications Control Module) are not supported.

Communications Capabilities

Serial communications are provided through the 15-pin D-sub connector on the installed power supply module, which connects directly to the CPU backplane interface. This native port operates strictly in SNP slave and SNP-X slave modes.

While PCM and CCM modules cannot be used, optional option modules—such as Ethernet, Profibus, FIP, GBC, GCM, and GCM+—can be installed in the baseplate slots to add networking capability.

Technical Specifications

Frequently Asked Questions

Q: Why does the IC693CPU323U lack a battery-backed real-time clock? A: The memory backup battery is housed inside the power supply module rather than on the CPU board itself. Unplugging or replacing the power supply disconnects the battery from the CPU RAM, preventing the maintenance of a continuous real-time clock circuit.

Q: Can I connect an expansion baseplate to the IC693CPU323U to increase I/O capacity? A: No, embedded CPU baseplates like the IC693CPU323U are non-expandable and do not feature an expansion bus connector for adding local expansion or remote baseplates.

Q: Are PCM and CCM communication modules compatible with this baseplate? A: No, the IC693CPU323U does not support PCM or CCM modules. For external network communication beyond SNP/SNP-X slave protocols, compatible option modules such as Ethernet, Profibus, or GCM must be used instead.