The Logging Application Applications
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Sixth Edition 253
On-Screen Messages
The messages listed in the table below may appear at the top of the screen 
during the Logging application.
Table 16 Logging Application On-Screen Messages
Agilent 8163A/B 
Message
Agilent 8164A/B 
Message
Description
OvR Overrange
One of the Power Meter channels has re-
ported an overrange.  The over-ranged 
value is clipped, statistical data is invalid.
NoH No Head
There is an Optical Head Interface mod-
ule inserted in the mainframe that does 
not have an Optical Head connected to it. 
No measurement is possible using this 
channel until you either:
• reconnect an Optical Head or 
• deselect this Optical Head channel as 
a power measurement channel.
NoD No Data
No data has been measured or measure-
ment is not yet finished. You cannot ac-
cess the Analysis Screen yet. Printout 
and file operations are not yet possible.