GE IC693PCM300D Series 90-30 Programmable Coprocessor Module (PCM)

Description

The GE IC693PCM300D (a revision variant of the IC693PCM300, with -D denoting a hardware/firmware iteration or manufacturing batch in GE Fanuc/Emerson Series 90-30 documentation) solves the problem of CPU overload in Series 90-30 PLC systems when handling complex serial communications, data manipulation, custom protocols, or computational tasks alongside core logic. In applications involving barcode scanners, scales, printers, weigh feeders, Modbus polling, ASCII report formatting, or math-heavy algorithms — common in batch processing, inventory tracking, or quality control — the main CPU can experience extended scan times, delayed I/O response, or insufficient memory for additional ladder. GE IC693PCM300D acts as a dedicated coprocessor with its own processor and memory, running independent MegaBasic (a structured BASIC dialect) programs while exchanging data with the PLC CPU via COMMREQ instructions or shared registers. It’s particularly valuable in process control environments requiring high reliability for auxiliary processing without compromising deterministic PLC performance.

GE IC693PCM300D mounts in any available slot (except CPU slot 1) on a modular Series 90-30 baseplate, serving as a programmable coprocessor module that executes MegaBasic applications independently of the main CPU. It features 160 KB total memory (with approximately 35 KB nominal user-available for MegaBasic programs after system overhead), dual serial ports (RS-232/RS-485 configurable via a shared front connector) for GE Fanuc CCM, Modbus RTU Master/Slave, or custom ASCII/binary protocols, and battery-backed RAM for retentive variables. Data transfer occurs through %R registers or COMMREQ blocks for triggering commands, monitoring status, and bidirectional exchange. The module supports string handling, file I/O, math functions, and foreground/background tasking. Positioned as a co-processing extension in the 90-30 architecture, GE IC693PCM300D offloads serial handling, protocol conversion, data logging, or calculations — freeing the CPU for primary control — with LEDs for COPROC (coprocessor OK), US1/US2 (user-defined), BD (battery low), P1/P2 (port activity), and RESTART button for resets.

Choosing GE IC693PCM300D enables efficient task partitioning that keeps main PLC scans fast and predictable while adding powerful auxiliary capabilities. Running MegaBasic independently, it handles serial polling, data formatting, or computations without scan time penalties, supporting applications like device interfacing or report generation. The dual ports and protocol flexibility reduce custom ladder or external converters, while COMMREQ-based control allows precise synchronization and error handling from the main program. Diagnostics via LEDs and fault tables speed troubleshooting, and the module’s design supports online edits in many cases. For legacy 90-30 users, GE IC693PCM300D maximizes installed assets, enabling protocol expansions or custom logic without CPU upgrades and ensuring critical system uptime in communication-intensive processes.

GE IC693PCM300D is commonly used in manufacturing for interfacing with barcode readers, scales, or printers, where it parses data, formats reports, or performs checksums before passing to the PLC for inventory or quality decisions. In utilities or batch processes, it’s applied for Modbus polling of instruments/meters or generating formatted logs via serial devices in process control environments. Chemical, food & beverage, or water treatment facilities deploy it for custom ASCII handling from analyzers or batch tracking, valuing independent execution and high reliability amid variable device interactions.

Related or alternative products in the GE Fanuc Series 90-30 coprocessor family include:

IC693PCM300 – Base model (without -D suffix; equivalent core specs).

IC693PCM301 – Higher-memory version (192 KB total, ~47 KB user MegaBasic) for larger programs.

IC693PCM311 – Highest-memory PCM (640 KB total, ~190 KB user) for complex applications.

IC693CMM321 – Ethernet module for TCP/IP/SRTP if shifting from serial coprocessing.

IC693CPU363 – High-memory CPU that can handle some coprocessor tasks natively.

IC693PWR330 – High-capacity power supply for coprocessor-heavy racks.

IC693CHS391 – 10-slot modular baseplate for systems including GE IC693PCM300D.

VersaMax PCM – Modern equivalent in newer Emerson platforms for migration.

Before installing GE IC693PCM300D, confirm modular baseplate (not for embedded CPU models like 311/313/323) and slot availability with sufficient power (e.g., IC693PWR321/330). Install the lithium battery for retentive memory/clock. Use Proficy Machine Edition to configure the slot, allocate %R windows, and set up COMMREQ triggers — load MegaBasic programs via serial tools like PCOP or TERMF. Ground the rack properly, connect serial cables per pinout, and commission by powering up, checking LEDs/self-test, and validating COMMREQ responses in the PLC.

Ongoing maintenance prioritizes status and program checks: monitor LEDs routinely (COPROC OK for health, P1/P2 for port activity, BD for battery low, FAULT for issues). Replace battery every 2–5 years or on indication to retain programs/variables. Inspect serial connectors annually for corrosion/loose fits. Review PCM faults and COMMREQ status in PLC diagnostics, trending errors. Firmware/program updates via serial align with Emerson releases, performed offline first. The single-slot design supports hot-swappable replacement in non-critical setups (power down recommended), with quick reload from backups.