IC697BEM713G FANUC IC697BEM713G Bus Transmitter-Expansion Board BEM713

GE Fanuc IC697BEM713G | Series 90-70 Bus Transmitter Module (BTM) — 500 KB/s / 50ft / 7 Expansion Racks / 1.4A / Revision G

Part Number: IC697BEM713G

Manufacturer: GE Fanuc

Revision: G

Series: Series 90-70 

Expanding the Series 90-70 System — Seven More Racks from One Module

The IC697BEM713G is the Bus Transmitter Module (BTM) for GE Fanuc's Series 90-70 PLC system. Its primary function is enabling rack expansion — the IC697BEM713G sits in the main CPU rack and extends the Series 90-70 local bus outward to up to seven additional expansion racks, each containing its own set of I/O and option modules. This makes the BTM the critical component in any Series 90-70 installation that requires more modules than a single rack can hold.

The expansion bus uses a daisy-chain topology. The BTM connects to the first Bus Receiver Module (IC697BEM711) in an expansion rack. That BRM connects to the next expansion rack's BRM, and so on through the chain. A terminating resistor (IC697ACC702) must be installed on the Expansion Port Out of the last BRM in the chain to close the network. The BTM manages all bus timing and data transfer for the complete chain of expansion racks.

The second function of the IC697BEM713G is its parallel programmer interface — the top connector on the module accepts the programming device (PC) connection for downloading and uploading PLC programmes to and from the CPU at 500 Kbytes per second. This combined function — rack expansion plus programming interface — in a single slot is a practical advantage in systems where panel real estate is limited.

Three green LED indicators on the module face provide instant status: MODULE OK confirms the CPU has completed BTM configuration and polled all expansion racks; Programmer Port Enabled shows active programmer communication; Expansion Port Enabled shows communication with the expansion bus receiver modules.

Key Specifications

IC697BEM713G Installation Notes

The IC697BEM713G must be installed to the right of any interrupt source modules in the rack, excluding slot 1. The 50-foot cable distance limit applies to the total cumulative length from the BTM to the last BRM in the expansion chain — not just from the BTM to the first BRM. Longer installations require careful cable route measurement. The last BRM in the daisy chain must have the IC697ACC702 terminating resistor installed on its Expansion Port Out connector to prevent signal reflections.

FAQ

Q1: What is the difference between a Bus Transmitter Module (BTM) and a Bus Receiver Module (BRM)?

The BTM (IC697BEM713G) installs in the main CPU rack and drives the expansion bus — it is the master of the local expansion bus, managing all timing and data transfers. The BRM (IC697BEM711) installs in each expansion rack and receives the bus signals from the BTM, making the expansion rack appear to the CPU as a seamless extension of the main rack. Every expansion rack requires one BRM; the system requires exactly one BTM.

Q2: Can the IC697BEM713G be installed in any slot of the Series 90-70 rack?

Not slot 1. The BTM must be installed to the right of any interrupt source modules in the rack. Slot 1 is reserved for interrupt sources in many Series 90-70 configurations. Check the Series 90-70 installation manual for the specific rack configuration requirements before selecting the BTM's slot.

Q3: Does the IC697BEM713G affect PLC programme performance when the expansion bus is fully loaded?

The BTM adds some overhead to the PLC scan in proportion to the amount of data exchanged with expansion rack modules. A fully loaded expansion bus with seven racks of I/O modules adds data transfer time at the 500 Kbytes/sec bus rate. For large expansion systems, account for this communication overhead in the total cycle time budget. GE Fanuc's Series 90-70 performance documentation provides scan time calculation guidance.

Q4: What is the significance of the "G" revision on the IC697BEM713G?

The G revision identifies a specific hardware production revision of the IC697BEM713 base module. Hardware revisions incorporate component updates, manufacturing changes, or reliability improvements while maintaining the same functional specification. All IC697BEM713 revisions serve the same BTM function. When ordering a replacement, any available revision is functionally compatible — revision matching is only necessary for certified system configurations where specific revision traceability is required.

Q5: Where is the IC697BEM713G sourced?

Through the GE Fanuc Series 90-70 aftermarket — Emerson Automation-related parts dealers, tested surplus suppliers, and repair centres specialising in the Series 90-70 platform. The IC697BEM713 in G and other revisions appears regularly in the 90-70 aftermarket given the large global installed base. Confirm the terminating resistor (IC697ACC702) is available with the BTM for new chain installations.