I'm trying to generate a pi/4 DQPSK signal with user defined bits. In the manual, it says the 4438C adds control bits but it doesn't specify what those are. Can someone clarify the length and values of these bits?
The E4438C allows user defined bits in numerous standard formats so it is difficult to answer this question specifically. User defined data in an unframed format will all be used as ‘payload’ data and no control bits are used. User defined data in a framed format will also be used as ‘payload’ data and the E4438C will add the framing control data in order to define the frame. The length of these bits will depend on the current format in use – this is done automatically and requires no action from the user. For users who want to create their own formats PRAM data can be used. In this mode the user needs to supply both ‘payload’ data and control bits. In each byte there are seven control bits and one ‘payload’ data bit. Of the seven control bits, the user needs to supply three.
Here is the byte- [bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0] Bits 1 thru 7 are control bits Bit 0 is the ‘payload bit Bits 2,6,7 are user supplied control bits Bit 1,3,4,5 are E4438C supplied control bits
More detailed information on all of the above can be found in the Creating and Downloading User-Data document -E4400-90561 http://cp.literature.agilent.com/litweb/pdf/E4400-90651.pdf
The E4438C allows user defined bits in numerous standard formats so it is difficult to answer this question specifically. User defined data in an unframed format will all be used as ‘payload’ data and
no control bits are used. User defined data in a framed format will also be used as ‘payload’ data and the E4438C will add the framing control data in order to define the frame. The length of
these bits will depend on the current format in use – this is done automatically and requires no action from the user.
For users who want to create their own formats PRAM data can be used. In this mode the user needs to supply both ‘payload’ data and control bits. In each byte there are seven control bits
and one ‘payload’ data bit. Of the seven control bits, the user needs to supply three.
Here is the byte- [bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0]
Bits 1 thru 7 are control bits
Bit 0 is the ‘payload bit
Bits 2,6,7 are user supplied control bits
Bit 1,3,4,5 are E4438C supplied control bits
More detailed information on all of the above can be found in the Creating and Downloading User-Data document -E4400-90561
http://cp.literature.agilent.com/litweb/pdf/E4400-90651.pdf
Regards -