GE IC697BEM711 Retrofit-Compatible Bus Expander for Legacy Systems

GE IC697BEM711 Retrofit-Compatible Bus Expander for Legacy Systems

The GE IC697BEM711 is a Bus Expansion Module designed for the GE Series 90-70 programmable logic controller platform — one of the most widely deployed industrial control architectures in process manufacturing, power generation, and discrete automation. As the Series 90-70 platform approaches end-of-life and OEM support becomes increasingly scarce, the IC697BEM711 remains a critical component for facilities that need to extend the operational life of their existing control infrastructure without committing to a full system replacement. NINERMAS maintains verified stock of the IC697BEM711 to support retrofit projects, emergency replacements, and planned system upgrades across global industrial sites.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

When integrating the IC697BEM711 into an ongoing retrofit or system expansion project, engineers must account for several interdependent components across the control cabinet. The IC697BEM711 functions as the transmitter side of a two-module bus expansion pair — it must be used in conjunction with the IC697BEM721 receiver module installed in the remote expansion rack. Both modules communicate over a dedicated expansion cable, and the integrity of this cable run is one of the most common sources of commissioning delays on retrofit sites.

Power budget verification is an essential first step. The IC697PWR711 and IC697PWR724 power supply modules each have defined output capacities, and adding an expansion rack introduces additional load. Before installing the IC697BEM711, calculate the total current draw of all modules in both the primary and expansion racks to confirm the existing power supplies can support the expanded configuration. If the budget is tight, a supplementary IC697PWR724 may be required in the expansion chassis.

Rack selection is equally important. The IC697CHS750 (5-slot), IC697CHS782 (12-slot), and IC697CHS790 (9-slot) are the standard Series 90-70 chassis options. The IC697BEM711 occupies one slot in the primary rack, while the IC697BEM721 occupies one slot in the remote rack. Slot addressing must be reconfigured in the hardware configuration tool — either Logicmaster 90-70 or Proficy Machine Edition — to reflect the expanded I/O map before the system is brought back online.

For sites running mixed I/O architectures, the IC697BEM711 expansion path supports the addition of analog input modules such as the IC697ALG230 and IC697ALG320, as well as discrete I/O modules including the IC697MDL340 and IC697MDL753. If the retrofit involves migrating from legacy relay logic to PLC-controlled outputs, the I/O module selection and terminal block wiring must be validated against the existing field wiring schedule. Signal isolators may be required where legacy 4–20 mA loops interface with newer I/O modules to prevent ground loops and signal degradation.

HMI integration is another consideration. Many Series 90-70 installations use legacy CIMPLICITY or iFIX SCADA screens that reference specific register addresses tied to the original rack configuration. When the IC697BEM711 is used to expand the I/O map, any new modules added to the expansion rack will occupy new register addresses. These must be mapped correctly in the HMI tag database to avoid display errors or control anomalies after the retrofit is complete. If the site is also upgrading the HMI hardware, this is an opportunity to migrate to a modern Proficy iFIX or CIMPLICITY platform while maintaining the same underlying PLC logic.

Communication protocol continuity is a frequent concern on sites where the Series 90-70 CPU — such as the IC697CPU772 or IC697CPU781 — communicates with upstream DCS or MES systems via SNP, SRTP, or Modbus TCP. The IC697BEM711 does not affect the CPU’s communication ports, so existing Ethernet or serial communication links remain intact after the expansion module is installed. However, if the retrofit includes replacing the CPU module itself, communication parameter re-entry and network re-commissioning will be required.

Downtime Control During System Migration

Minimizing unplanned downtime is the primary operational concern for any facility undertaking a Series 90-70 retrofit. The IC697BEM711 replacement process is designed to be executed during a planned maintenance window, and with proper preparation, the physical swap can typically be completed in under two hours.

Before the maintenance window begins, the existing hardware configuration should be exported from Proficy Machine Edition or Logicmaster 90-70 and saved to a secure backup location. The PLC program — including all ladder logic, function blocks, and data tables — should be uploaded from the CPU and archived. This ensures that if any issue arises during the retrofit, the original program can be reloaded without delay.

During the swap, the expansion cable between the primary rack and the remote rack should be inspected for damage, connector wear, and secure seating. A faulty cable is one of the most common causes of BEM711/BEM721 communication faults and can be mistaken for a module failure. If the cable is original to the installation, replacement with a new cable of the same specification is recommended as a precautionary measure.

After the IC697BEM711 is installed and the system is powered up, the hardware configuration should be downloaded to the CPU and the I/O fault table cleared. Each I/O module in the expansion rack should be verified for correct status indication before the system is returned to automatic mode. Field instruments connected to the expansion rack I/O should be checked for correct signal levels, and any analog modules should be verified against their calibration records. The entire commissioning sequence should be documented and retained as part of the site’s maintenance record.

NINERMAS ships all IC697BEM711 units with a functional test certificate confirming the module has been powered and verified prior to dispatch. This pre-shipment testing reduces the risk of receiving a non-functional module and supports the goal of completing the retrofit within the planned maintenance window.

Retrofit Support FAQ

Q: Is the IC697BEM711 a direct drop-in replacement for a failed unit in an existing Series 90-70 system?
A: Yes. The IC697BEM711 is a direct replacement for any existing IC697BEM711 installed in a Series 90-70 primary rack. No program changes are required. The hardware configuration in Proficy Machine Edition or Logicmaster 90-70 does not need to be modified, as the module occupies the same slot and performs the same function as the original unit.

Q: What commissioning steps are required after installing the replacement IC697BEM711?
A: After physical installation, power up the rack and verify that the BEM711 status LED indicates normal operation. Clear any I/O faults from the CPU fault table and confirm that all modules in the expansion rack are communicating correctly. Check field signal levels on analog and discrete I/O modules before returning the system to automatic control. Document the commissioning steps and retain the functional test certificate supplied with the module.

Q: Can the IC697BEM711 be used to expand a Series 90-70 system that currently has no expansion rack?
A: Yes. The IC697BEM711 (transmitter) installed in the primary rack and the IC697BEM721 (receiver) installed in a new expansion chassis — such as the IC697CHS750 or IC697CHS782 — together enable the addition of a remote I/O rack. The new rack must be configured in the hardware configuration tool, and the power budget of the primary rack power supply must be confirmed before proceeding.

Q: What warranty and supply terms apply to NINERMAS stock of the IC697BEM711?
A: All IC697BEM711 units supplied by NINERMAS carry a 12-month warranty from the date of shipment. Each unit is functionally tested prior to dispatch and ships with a test certificate. NINERMAS maintains ongoing inventory of the IC697BEM711 and related Series 90-70 components to support both emergency replacement and planned retrofit projects. Contact sale@ninermas.com or +0086 187 5021 5667 for availability and lead time confirmation.