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Cisco ONS 15200 Series DWDM Systems

Field Notice: *Expired* FN - 17157 - ONS15200 - Increase Clip Peltier Current Thresholds


Revised June 2, 2008
January 16, 2002



NOTICE:

THIS FIELD NOTICE HAS BEEN EXPIRED AND IS NO LONGER MAINTAINED OR UPDATED BY CISCO.

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE, WARRANTY OR SUPPORT. USE OF THE INFORMATION ON THIS FIELD NOTICE OR MATERIALS LINKED FROM THIS FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Products Affected

Product

Comments

CHxx/M/P/SC/15200=

CLIP Chan xx, Med Range, Protected, SC Connector,15200

CHxx/L/P/SC/15200=

CLIP Chan xx, Long Range, Protected, SC Connector,15200

CHxx/M/U/SC/15200=

CLIP Chan xx, Med Range, Unprotected, SC Connector,15200

CHxx/L/U/SC/15200=

CLIP Chan xx, Long Range, Unprotected, SC Connector,15200

?

CHxx = Chan 23, 25, 27, 29, 31, 33, 35, 37, 43, 45, 47, 49, 51, 53, 55 or 57

  

Problem Description

All Client Layer Interface Port (CLIP) cards deployed in the field have threshold settings for the Peltier current that are too low. This may cause an incorrect display of the "low" (or "high") warning alarm.

NCB:>show alarm
  --------------+------+----------------------+---------------
  name          |slot  | alarm point          | status
  --------------+------+----------------------+---------------
  ...
  mcu mcu_1_1   |  6   | dwdm peltiercurrent  | lw (-63.3 pc)
  mcu mcu_1_1   |  7   | dwdm peltiercurrent  | lw (-61.8 pc)
  ...

Background

The current threshold numbers for the percentages are as follows:

hat (high alarm)    : 80%
     hwt (high warning)  : 60%


     lwt (low warning)   : -60%
     lat (low alarm)     : -80%

The laser temperature is calibrated and kept constant through regulation of the Peltier current. For the alarm levels, the percentage is based on the maximum heating and cooling current that the CLIP can produce. The alarm thresholds will be the same for all CLIPs.

Example :

clip_test:#list recursive
  clip_test:...
   dwdm:...
    peltiercurrent:
     status = lowwarning 
     value  = -63.3 pc
     hat    =  80.0 pc
     hwt    =  60.0 pc
     lwt    =  -60.0 pc
     lat    =  -80.0 pc
     unit   =  percent 
     pmvalue=  uninitialised

Problem Symptoms

The reason for increasing the threshold levels is a change in maximum available Peltier cooling current from 1.2 A to 900 mA. Initial CLIP design used 60 percent as the Peltier current warning threshold. This was based on a maximum cooling current of 1.2 A for CLIP revision 3.0. All CLIPs revision 3.2 and higher, which are the only ones deployed in the field, have a maximum cooling current of 900 mA. As a result, the Peltier current threshold levels should be raised to 80 percent to keep the current level that triggers the alarm constant. Although the threshold window is increased, the warning will now be raised at the intended cooling current.

Workaround/Solution

In order to reflect the lower maximum cooling current used by the CLIPs, readjust the Peltier current threshold to :

hat (high alarm)    : 95%
  hwt (high warning)  : 80%

  lwt (low warning)   : -80%
  lat (low alarm)     : -95%

Example :

clip_test:#list recursive
  clip_test:...
   dwdm:...
    peltiercurrent:
     status = normal
     value  = -63.3 pc
     hat    =  95.0 pc
     hwt    =  80.0 pc
     lwt    =  -80.0 pc
     lat    =  -95.0 pc
     unit   =  percent 
     pmvalue=  uninitialised

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: