STBNIP2212 Loses Modbus Communications Under a Specific Condition



Release Notice

The purpose of this resolution is to inform users of STB Ethernet NIM's (Modbus TCP and Ethernet/IP) of a communication issue that may occur under a specific condition.

Goals and Symptoms

If an STBNIP2212 was powered on for 828 consecutive days, it would lose Modbus communications for 20 minutes, recover on its own and will not fault again with this behavior for another 828 days.

Facts and Changes


    • STBNIP2212 RoHs versions (RoHs versions are identified with an SV equal to or greater than 2.70)
      • RoHs is the acronym for Restriction of Hazardous Substances. RoHS, also known as Directive 2002/95/EC, originated in the European Union and restricts the use of specific hazardous materials found in electrical and electronic PRODUCTS. The substances banned under RoHS are lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (CrVI), polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE).
    • STBNIP2212 non-RoHs versions (non-RoHs versions are identified with an SV less than 2.70)
    • STBNIC2212

Causes and Fixes

CauseThe 828 consecutive days powered on relates to an internal clock value in the STBNIP2212. When this specific clock value is reached, an issue occurs with the ARP cache creating a 20 minute Modbus TCP communication loss. After this 20 minute period, the communications will recover on its own. ICMP service may or may not be immediately affected by this event but will recover at the same time as Modbus TCP communications.

How to Manage the Issue with Existing Firmware
If at any time, the NIP is power cycled, its clock count value resets to zero and starts a new 828 day operating period. This can be done during any scheduled maintenance period within the 828 day time frame to avoid this event.

New firmware for each of the 3 affected PRODUCTS will be posted to resolve this issue but a schedule for availability was not confirmed at the time of this posting.

This Resolution will be updated with specific Exec version details when the updated firmware becomes available.


Legacy KB System (APS) Data: RESL212447 V2.0, Originally authored by DaDz on 09/06/2013, Last Edited by DaDz on 09/18/2013
Related ranges: Modicon STB