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Why am I receiving a "serial communication lost" message from my Network Management Card?


I am receiving a "serial communication lost" message from my Network Management Card or Web/SNMP Card.

Product Line
  • Web/SNMP Card - AP9606
Devices with an embedded Web/SNMP Card include (but are not limited to): Environmental Monitoring Unit 1 (AP9312TH)
  • UPS Network Management Card 1 (NMC1) - AP9617, AP9618, AP9619

  • All serial numbers
  • Older firmware revisions beginning with v1.X, 2.X and 3.X

This problem has only been seen on a couple of occasions. It typically occurs if the UPS_ID and Last Battery Replacement Date are not allocated some value, and the Symmetra has an Web/SNMP Management Card or Network Management Card installed. After a card is installed in a Symmetra, the Event Log in the PowerView fills up with false events. These may also be recorded in PowerChute's Event Log.

An example of this is as follows:

  • UPS Self Test Failed
  • Shutdown Low Battery
  • Shutdown Delay
  • Shutdown until Power Return
  • Bypass Relay Fault
  • Fault Internal Temp
  • Power Restored
  • UPS in Bypass
  • UPS out of Bypass
  • Load Turned on
  • Power Restored
  • Self Test failed

All of these events happen without justification. The best way to guarantee that the events are false is to look at the log and you will see that several of the events (3 or more) will have the same time stamp. Additionally, these messages disappear upon removal of the card.


Assuming your Network Management Card firmware is up to date, the problem most likely lies with the Symmetra or Smart-UPS and its synchronization of the accessories, and is solved easily by updating the values in the two fields listed below. It is unlikely that the card itself is faulty, and thus replacing it will not solve the problem.

If the last "battery replacement date" field is not populated in the interface of the Web/SNMP Management Card (AP9606) or Network Management Card (AP9617/AP9618/AP9619), you may receive the erroneous messages. Quite often you will see the message Serial Communication Lost displayed (a lot of times from a Symmetra UPS). You can update this field with the following procedure:

  1. Remove all Smart Slot accessories, including the Web/SNMP Management Card or Network Management Card from the UPS. Disconnect the Powerview Display.
  2. Connect the black smart signaling cable (940-0024/940-1524) from your Symmetra to a computer with Hyperterminal or a terminal emulation program installed. Verify communication by typing Shift Y: the reply will be SM. This will confirm that you have asynchronous communication established.
  3. Type "x" which should be followed by 8 characters or possibly blank.
  4. Type "-" followed by any date in the format MM/DD/YY (e.g. 01/01/00).
  5. Type "x" and it will now reply with whatever you entered (e.g. 01/01/00).
  6. You are now finished. Disconnect from Hyperterminal and check the Event Log in the PowerView. It will be back to normal now.
  7. Reinstall the Powerview, any accessories, and the Web/SNMP Management Card or Network Management Card.

Note: If this procedure is not applicable to your UPS or scenario, please review knowledge base FA156045 for additional information

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UPS Network Management Cards
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