Allen-Bradley 1747-OCPCM2 Replacement for SLC 500

Product Overview

Allen-Bradley 1747-OCPCM2 Replacement for SLC 500: Seamless Migration & Upgrade Solution

The Allen-Bradley 1747-OCPCM2 is a PCMCIA-type open controller interface module designed for the SLC 500 programmable controller platform. As legacy SLC 500 systems approach end-of-life and spare parts become increasingly scarce, plant engineers and maintenance teams face mounting pressure to source verified replacement units or plan a structured migration path. TOPNLMS supplies tested 1747-OCPCM2 modules with a 12-month warranty, enabling facilities to extend operational life or execute a controlled upgrade without unplanned downtime.

Whether your facility is running a standalone SLC 5/03, SLC 5/04, or SLC 5/05 processor in a 1746 modular chassis, or integrating the SLC 500 platform into a broader DH+ or DH-485 network, the 1747-OCPCM2 provides the PCMCIA card interface required for open controller communication and programming access. This module slots directly into the open controller slot of compatible SLC 500 processors, maintaining the original wiring, rack geometry, and I/O addressing without modification.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful SLC 500 system migration or spare-parts replacement rarely involves a single module in isolation. When sourcing the 1747-OCPCM2, most plant engineers simultaneously evaluate the broader control architecture to ensure continuity across the entire panel. The SLC 5/04 processor module, for example, is the most common host for the 1747-OCPCM2 open controller slot, and maintaining a tested spare processor alongside the PCMCIA interface card eliminates a critical single point of failure.

For facilities running DH+ networks, the 1747-SDN DeviceNet Scanner or 1747-KE DH-485 to RS-232C interface module may also require attention during the same maintenance window, particularly if the communication backbone is being restructured as part of a broader migration from legacy SLC 500 to a ControlLogix or CompactLogix platform. In such cases, the 1756-DHRIO ControlLogix DH+/Remote I/O bridge module is frequently specified to preserve existing DH+ field device wiring while the controller tier is upgraded.

Within the 1746 chassis itself, digital I/O modules such as the 1746-IB16 (16-point 24VDC input) and 1746-OB16 (16-point 24VDC output) are standard companions to the SLC 500 processor. If the chassis backplane or power supply — typically the 1746-P4 or 1746-P7 — shows signs of age, replacing these components in the same service cycle reduces the risk of a secondary failure shortly after the primary repair. The 1746-A10 10-slot chassis is a common platform for mid-size SLC 500 installations and is worth inspecting for backplane integrity during any module swap.

For programming and commissioning, a 1747-UIC USB-to-DH-485 interface cable or a 1747-CP3 programming cable is required to connect a laptop running RSLogix 500 to the SLC 500 processor. Ensuring the programming cable is available on-site before the maintenance window begins is a basic but frequently overlooked step that can add hours to an otherwise straightforward module replacement.

In applications where the SLC 500 system interfaces with third-party SCADA, HMI, or MES platforms via serial or Ethernet, the 1747-SCNR SLC 500 ControlNet Scanner or a PanelView 600 HMI terminal connected via DH-485 may also be part of the upgrade scope. Verifying communication parameter compatibility — baud rate, node address, and message routing — before powering up the replacement module prevents commissioning delays and ensures the control system returns to normal operation within the planned maintenance window.

Retrofit Guidance FAQ

Q: Does replacing the 1747-OCPCM2 require any wiring changes?
A: No. The 1747-OCPCM2 is a PCMCIA card that inserts into the open controller slot of the SLC 500 processor. It does not connect to field wiring directly. No terminal block or I/O wiring modifications are required for a direct replacement.

Q: Will my existing RSLogix 500 program need to be modified?
A: No program changes are required for a like-for-like replacement. The 1747-OCPCM2 restores the original open controller interface functionality. If you are migrating to a new processor series (e.g., CompactLogix L3x), a program conversion using the RSLogix 500 to Studio 5000 migration utility will be necessary.

Q: Is the 1747-OCPCM2 compatible with all SLC 500 processor variants?
A: The module is compatible with SLC 5/03, SLC 5/04, and SLC 5/05 processors that include an open controller slot. It is not applicable to the fixed SLC 5/01 or SLC 5/02 processors, which do not have an open controller interface.

Q: What communication protocols does the 1747-OCPCM2 support?
A: The supported protocols depend on the host processor. The SLC 5/04 supports DH+ and RS-232; the SLC 5/05 adds Ethernet/IP. The 1747-OCPCM2 itself provides the PCMCIA interface layer; protocol capability is determined by the processor firmware and network configuration.

Q: Can the 1747-OCPCM2 be used in a migration from SLC 500 to ControlLogix?
A: Yes, as an interim measure. The module can maintain SLC 500 operation while the migration is planned and tested in parallel. For the final cutover, the ControlLogix platform with a 1756-DHRIO bridge module is the recommended path to preserve existing DH+ field device wiring.

Q: What physical space is required for installation?
A: The 1747-OCPCM2 occupies the PCMCIA open controller slot on the SLC 500 processor faceplate. No additional chassis slot or panel space is required. The module is self-contained within the processor unit.

Warranty Assurance

Every 1747-OCPCM2 unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. Prior to dispatch, each module undergoes a functional verification process including power-on testing and communication interface checks to confirm operational integrity.

In the event of a confirmed module defect within the warranty period, TOPNLMS will arrange a replacement unit or issue a credit at the buyer’s discretion. Our after-sales response target is one business day for warranty claims, with replacement units typically dispatched within three to five business days depending on stock availability and destination.

All units are shipped from Xiamen, China, with full export documentation. Standard shipping options include DHL Express, FedEx International Priority, and sea freight for bulk orders. Expedited air freight is available for urgent replacement requirements where minimizing downtime is the primary concern.

For procurement teams requiring traceability documentation, test reports, or batch certification, please contact our sales team directly. We support purchase orders, proforma invoices, and standard B2B procurement workflows for industrial buyers globally.

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