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Modbus Plus Active LED goes out on Momentum MBPL Communication Adapters

Release Notice

The purpose of this resolution is to inform users of Momentum Modbus Plus Communication Adapters of a problem where the Modbus Plus active LED goes out on the adapter and the module drops off the Modbus Plus network.

Goals and Symptoms

The Modbus Plus LED may go out after a short time operating on a Modbus Plus network. Power cycling the module will allow it to operate for a short time until the same problem occurs.

Facts and Changes

The PRODUCTS affected by this Resolution are:
170PNT11020 Modbus Plus Communication Adapter, IEC compliant
170PNT16020 Modbus Plus Communication Adapter, IEC compliant
170NEF11021 Modbus Plus Communication Adapter, 984 compliant
170NET16021 Modbus Plus Communication Adapter, 984 compliant

Causes and Fixes

Some Modbus Plus Communication Adapters that were manufactured contain an incorrect ASIC part: KLSI KS152JB3. The correct part should be either an Intel N80C152JC or KLSI KS152JB4.

Some units with a manufacturing date (serial number) code of 210510xxxx to 210518xxxx are suspect and should be evaluated before exchanging.

Follow the procedure below to identify the part.

To remove the PC board from the plastic case, pry the plastic case away from the PC board at the arrows (on the inside of the tabs), lifting the board outward at the same time.
When the PCB is removed, turn the board over and read the manufacturer of the large IC noted. Return the module if the part is labeled: KLSI - KS152JB3. The module is good if the part is either a KLSI - KS152JB4 or Intel - N80C152JC.
To reinstall the PCB, slide the PC board under the tabs at location A first. Then, push down on the board at location B until it snaps under the B tabs.
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